TGS ASA

Investor Presentation • Oct 23, 2025

Forward-Looking Statements

All statements in this presentation other than statements of historical fact are forward-looking statements, which are subject to a number of risks, uncertainties and assumptions that are difficult to predict and are based upon assumptions as to future events that may not prove accurate. These factors include volatile market conditions, investment opportunities in new and existing markets, demand for licensing of data within the energy industry,

operational challenges, and reliance on a cyclical industry and principal customers. Actual results may differ materially from those expected or projected in the forward-looking statements. TGS undertakes no responsibility or obligation to update or alter forward-looking statements for any reason. All financial numbers in this presentation are based on pro-forma unless stated otherwise.

TGS Q3 Highlights¹

• Q3 Revenues of USD 388 million vs. USD 308 million in Q2 2025
• Q3 EBITDA of USD 242 million (62% margin) driven by strong cost focus
• Q3 EBIT of USD 105 million (27% margin)
• Order inflow of USD 436 million total order backlog of USD 473 million
• Strong cash flow net debt reduced to USD 432 million vs. USD 479 million in Q2 2025
• Maintaining dividend of USD 0.155 per share
• 2025 capex guidance² reduced to USD 110 million vs. USD 135 million earlier

Business Update

Q3 2025 Data Acquisition Activity¹

¹Vessel operations are based on six streamer vessels. The Ramform Tethys started the quarter offshore Norway and moved to Brazil during August to commence a multi-client program, hence seven vessel icons on the map.

Multi-Client Update

6

Financials in millions USD1	Q3 2025	Q3 2024
Multi-client sales²	226	277
Multi-client investment	86	129
Sales-to-investment LTM	2.1	2.1

• PAMA Phase II offshore Brazil
• Streamer survey in Equatorial Margin area
• Megabar Extension Phase I
• Joint venture streamer survey in Equatorial Margin area offshore Brazil
• Amendment West-1 in the Gulf of America
• Ultra-long offset OBN survey over legacy streamer data

¹Financials are based on revenues measured by applying the percentage-of-completion method to early sales and accelerated amortization. ²Multi-client business unit revenues include joint venture revenue on certain projects.

Historical Multi-Client Performance

• Last Twelve Months sales/investment 2.1x in Q3 2025
• In line with average performance since Q1 2023
• Strong Q3 sales from multiclient library

Marine Data Acquisition Update

Financials in million USD¹	Q3 2025	Q3 2024
OBN contract revenues	87	127
Streamer contract revenues	127	164
Total gross revenues	215	291
EBITDA margin	36%	26%

• Awarded streamer contract in the Mediterranean
• Commenced acquisition in Q3
• Secured large streamer contract offshore Indonesia
• Scheduled to commence in Q4
• Duration of ~8 months
• Mostly 3D, with last month dedicated to 4D
• Awarded streamer acquisition contract in Africa
• Q4 start with ~50 days duration
• Secured OBN contract in Gulf of America
• Commence in Q4 2025
• Duration of ~4.5 months

¹Financials are based on revenues measured by applying the percentage-of-completion method to early sales and accelerated amortization.

New Energy Solutions Update

Financials in million USD	Q3 2025	Q3 2024
NES contract revenues	18	16
NES multi-client revenues	5	3
Total NES revenues	23	19
EBITDA margin	27%	22%

• Awarded UHR-3D contract offshore Norway
• Commenced acquisition early July
• Duration of ~25 days
• Acquired CCS contract offshore Norway
• Continues collaboration with Equinor by providing Prediktor Data Gateway Solution to their Empire Wind project

Imaging & Technology Update

Financials in million USD	Q3 2025	Q3 2024
Gross imaging revenues	32	26
External Imaging revenues	20	10
EBITDA margin	29%	-3%

• Enhanced strategic focus on external imaging market has resulted in significant revenue growth and increasing market share
• Significant reduction of HPC cost from added scale
• Expect continued growth in external imaging revenues
• Substantial margin improvement

Financials

Group Financials

Continued Focus on Cost Optimization

• Continued focus on cost efficiency and asset optimization has resulted in substantial cost reductions
• 2025 guidance for gross operating expenses reduced USD 100 million from originally ~USD 1,050 million to USD 950 million currently

Profit & Loss

Produced

(MUSD)	Q3 2025	Q3 2024	Change	YTD 2025	Pro forma YTD 2024	Change
Multi-client revenues	216.8	280.2	-23%	403.5	708.9	-43%
Contract revenues	171.4	220.7	-22%	743.3	605.4	23%
Total revenues	388.1	500.9	-23%	1,146.8	1,314.3	-13%
Cost of sales	50.0	107.3	-53%	235.3	293.0	-20%
Personnel cost	69.0	87.5	-21%	187.1	250.7	-25%
Other operational costs	27.5	26.1	5%	72.6	76.7	-5%
EBITDA	241.6	280.0	-14%	651.8	693.9	-6%
Straight-line amortization	60.5	65.3	-7%	182.8	214.0	-15%
Accelerated amortization	13.3	49.5	-73%	133.5	138.6	-4%
Impairments	2.3	1.3	83%	2.3	1.3	83%
Depreciation	61.0	59.5	2%	183.6	165.4	11%
Operating profit (EBIT)	104.5	104.4	0%	149.6	174.6	-14%
Financial income	4.3	4.3	0%	9.9	14.1	-30%
Financial expenses	-19.4	-17.9	8%	-68.8	-75.3	-9%
Exchange gains/losses	-4.0	6.0	-166%	-6.0	-12.9	-53%
Result before taxes	85.4	96.7	-12%	84.7	100.5	-16%

Cash Flow

Produced

(MUSD)	Q3 2025	Q3 2024	YTD 2025	YTD 2024
Produced EBITDA	241.6	280.0	651.8	544.1
Paid tax	(11.1)	(3.2)	(61.6)	(16.5)
Change in balance sheet items	11.5	(11.9)	91.5	(80.2)
Cash flow operations	242.0	264.9	681.7	447.4
Capitalized multi-client investments	(85.9)	(129.4)	(330.1)	(248.2)
Non-cash capitalization of multi-client investments	9.1	9.2	29.7	12.9
Paid multi-client investments capitalized in other periods	0.1	(2.1)	0.5	(10.9)
Paid multi-client investments	(76.8)	(122.3)	(299.9)	(246.2)
Capex	(21.8)	(23.8)	(73.7)	(65.5)
Investments through M&A	-	-	-	(58.2)
Interest received	4.2	0.4	8.9	3.2
Cash flow from investment activities	(94.4)	(58.9)	(364.7)	(279.9)
Net change in interest-bearing debt and leasing	(32.7)	(41.5)	(83.4)	(23.7)
Interest paid	(34.3)	(35.6)	(47.2)	(41.7)
Dividend payments	(30.4)	(27.5)	(91.3)	(64.1)
Other changes in equity and buybacks	0.0	(18.8)	0.0	(18.8)
Cash flow from financing activities	(97.4)	(123.4)	(221.8)	(148.3)
Net change in cash and cash equivalents	50.2	82.6	95.2	19.2
Cash and cash equivalents at the beginning of period	166.5	125.0	122.8	196.7
Net realized currency gains/(losses)	(4.0)	6.1	(5.3)	(2.2)
Cash and cash equivalents at the end of the period	212.7	213.8	212.7	213.8

Net Debt Development – Targeted Capital Structure

Decreasing net debt towards targeted range (MUSD)

Balance Sheet

IFRS

Dividends

The Board has resolved to maintain the quarterly dividend of USD 0.155 per share

• Ex date 30 October 2025 – payment date 13 November 2025

TGS has returned more than USD 1.6 bn to shareholders through dividends and buybacks since 2010

Outlook

Steeper Decline Curves Requires Increased Investment

• 90% of upstream oil and gas investment is used to offset production declines not meet demand growth
• Absent investment in new or existing projects from 2025 oil production would decline 8% p.a. according to IEA
• Equivalent to loosing more than current production from Brazil and Norway every year for the next 10 years
• Steeper decline rates requires higher investments to offset them

CEOs Recently Highlighting the Exploration Challenge

"Oil market oversupply is likely to be a short-term issue, with demand from emerging economies set to make meeting global energy demand more challenging in the medium-longer term." Darren Woods, CEO ExxonMobil

"We had a decade... where people didn't explore. It's going to have an impact. If it doesn't happen, there will be a supply crunch."

Amin Naser, CEO Saudi Aramco

"This non-OPEC supply, which today is impacting the market, from Brazil, Guyana and shale oil will plateau, there is a limit to this growth."

Patrick Pouyanne, CEO TotalEnergies

"Discoveries have gone way down, investment in exploration has gone way down but it's not just investment that's the problem, we just aren't finding big reservoirs anymore."

Vicki Hollub, CEO Occidental

3D Streamer Contract Tenders

Value of active contract streamer tenders (USDm)

• Seasonally low value of outstanding streamer tenders
• Integrated business model enables TGS to establish long-term agreements and bid selectively
• Recent uptick in multi-client activity and pre-funding level (not reflected in chart)

OBN Market Development

Acquisition revenues OBN mid to deepwater market OBN acquisition revenues (USDm) mid to deepwater segment

• 2025 OBN mid to deepwater market revenues expected to be slightly higher than in 2023
• 2025 market revenues decline 10-12% vs. 2024
• Commenced tendering process for 2026 summer season
• More fragmented supply side variable degree of discipline

2025 Guidance

• Investment of USD 425-475 million (unchanged)

• Approximately 70% of the investment is expected to be acquired with TGS' own capacity

• ~USD 135 million

• Excluding approximately 10 million of integration related capex

MULTI-CLIENT INVESTMENT CAPITAL EXPENDITURES GROSS OPERATING COST UTILIZATION

• Target ~USD 950 million (unchanged)*

• Expect improved utilization of 3D streamer fleet (unchanged)
• Lower OBN acquisition activity compared to 2024 (unchanged)

24 *Before merger related costs

Order Backlog & Inflow

Total Backlog in MUSD

Order Inflow in MUSD Expected timing of Marine Data Acquisition backlog revenue recognition

TGS Booked Positions¹

Booked streamer work in vessel months

• Q4 streamer geo-markets:
• Contract work in Africa and Asia
• Multi-client in Brazil
• Q4 OBN geo-markets:
• Contract work in GoA
• Multi-client in GoA

Booked OBN work – Normalized crew count

• Expect multi-client investment of ~USD 120 million in Q4 2025
• Utilization expectations Q4 2025
• Vessel utilization ~in line with Q3
• Normalized OBN crew count of ~1.8

¹As of 21 October 2025.

²Booked positions are for six active 3D streamer vessels and include contracts, planned steaming and yard time, as well as multi-client programs TGS has firm plans to do and vessel capacity is allocated, but where all pre-funding is not necessarily secured. Streamer and OBN plans are subject to changes depending on project execution and other external factors TGS is not in control of.

Q3 2025

Summary

• Solid performance on financial key figures
• Net debt reduced to USD 432 million
• Scrutinizing cash outflow reducing 2025 capex by ~USD 25 million
• Short-term market development sensitive to oil price, long-term market outlook remains positive
• Maintaining dividend of USD 0.155 per share

Thank you

Questions?

Appendix

IFRS Backlog & Inflow

Total Backlog in MUSD

Order Inflow in MUSD Timing of expected recognition of Early Sales contract backlog

IFRS - Early Sales backlog accounts for USD 630 million of the total backlog

IFRS – Profit & Loss¹

(MUSD)	Q3 2025	Q3 2024	Change	YTD 2025	YTD 2024	Change
Total revenues	424.4	451.1	-6%	1,254.7	827.5	52%
Cost of sales	50.0	107.3	-53%	235.3	184.2	28%
Personnel cost	69.0	87.5	-21%	187.1	152.0	23%
Other operational costs	27.5	26.1	5%	72.6	62.6	16%
EBITDA	277.9	230.2	21%	759.7	428.8	77%
Straight-line amortization	60.5	65.3	-7%	182.8	145.0	26%
Accelerated amortization	38.9	44.2	-12%	235.5	54.9	329%
Impairments	2.3	1.3	83%	2.3	1.3	83%
Depreciation	61.0	59.5	2%	183.6	122.5	50%
Operating result	115.2	59.9	92%	155.5	105.1	48%
Financial income	4.2	4.3	-2%	8.9	6.8	31%
Financial expenses	-19.4	-17.9	8%	-68.8	-26.1	164%
Exchange gains/losses	-4.0	6.0	-166%	-6.0	-5.8	4%
Gains/(losses) from JV	0.1	0.0	n/a	1.0	0.0	n/a
Result before taxes	96.1	52.3	84%	90.6	80.1	13%
Tax cost	34.1	14.8	131%	79.2	23.9	232%
Net income	62.0	37.5	65%	11.4	56.2	-80%
EPS (USD)	0.32	0.19		0.06	0.33
EPS fully diluted (USD)	0.31	0.19		0.06	0.33

¹Produced revenues is USD 388.1 million in Q3 2025. Produced revenue is calculated measuring the part of multi-client sales committed prior to completion of a project on a percentage of completion basis. ²Produced accelerated amortization is USD 13.3 million in Q3 2025. Produced Accelerated amortization of multi-client library is calculated on percentage of completion basis.

IFRS – Cash Flow

(MUSD)	Q3 2025	Q3 2024	Change	YTD 2025	YTD 2024	Change
Operating activities:
Profit before taxes	96.1	52.3	84%	90.6	80.1	13%
Depreciation/amortization/impairment	162.6	170.3	-4%	604.2	323.6	87%
Changes in accounts receivable and accrued revenues	11.2	6.3	77%	179.1	-31.7	-665%
Changes in other receivables	14.5	32.8	-56%	-15.6	35.0	-144%
Changes in other balance sheet items	-31.4	6.4	-594%	-115.1	56.9	-302%
Paid taxes	-11.1	-3.2	251%	-61.6	-16.5	273%
Net cash flows from operating activities	242.0	264.9	-9%	681.7	447.4	52%
Investing activities:
Investments in tangible and intangible assets	-21.8	-23.8	-8%	-73.7	-65.5	13%
Investments in multi-client library	-76.8	-122.3	-37%	-299.9	-246.2	22%
Investments through mergers and acquisitions	0.0	86.8	-100%	0.0	86.8	-100%
Interest received	4.2	0.4	1055%	8.9	3.2	178%
Net change in interest bearing receivables	0.0	0.0	n/a	0.0	-58.2	-100%
Net cash flows from investing activities	-94.4	-58.9	60%	-364.7	-279.9	30%
Financing activities:
Loan proceeds	0.0	72.0	-100%	70.0	130.2	-46%
Loan repayment	0.0	-84.0	-100%	-53.1	-84.0	-37%
Interest paid	-34.3	-35.6	-4%	-47.2	-41.7	13%
Dividend payments	-30.4	-27.5	11%	-91.3	-64.1	42%
Repayment of lease liabilities	-32.7	-29.5	11%	-100.3	-70.0	43%
Paid in equity	0.0	-0.3	-100%	0.0	-0.3	-100%
Purchase of own shares	0.0	-18.5	-100%	0.0	-18.5	-100%
Net cash flows from financing activities	-97.4	-123.4	-21%	-221.8	-148.3	50%
Net change in cash and cash equivalents	50.2	82.6	-39%	95.2	19.2	397%
Cash and cash equivalents at the beginning of
period	166.5	125.0	33%	122.8	196.7	-38%
Net unrealized currency gains/(losses)	-4.0	6.1	-166%	-5.3	-2.2	144%
Cash and cash equivalents at the end of period	212.7	213.8	0%	212.7	213.8	0%

Segment Financials

Q3 2025 (USD millions)	Multi-client	Marine Data Acquisition	New Energy Solutions	Imaging	Shared services	Eliminations	Group
External revenues	225.5	119.1	22.6	20.1	0.9	-	388.1
Inter-segment revenue	-	95.7	-	11.8	-	(107.5)	(0.0)
Costs	22.5	137.1	16.5	22.5	42.2	(94.3)	146.5
EBITDA	202.9	77.8	6.1	9.4	(41.4)	(13.3)	241.6
Depreciation							61.0
Straight-line amortization of multi-	-client library						60.5
Produced accelerated amortization	on of multi-client library						13.3
Impairment of the multi-client libra	ary						2.3
Operating profit (EBIT)							104.5
Organic multi-client investments							85.9

Q3 2024 (USD millions)	Multi-client	Marine Data Acquisition	New Energy Solutions	Imaging	Shared services	Eliminations	Group
External revenues	277.4	193.7	19.4	10.2	0.2	0.0	500.9
Inter-segment revenue	-	97.1	-	15.8		(112.9)	-
Costs	18.6	214.1	15.2	26.8	42.9	(96.6)	220.9
EBITDA	258.7	76.7	4.2	(0.7)	(42.7)	(16.3)	280.0
Depreciation							59.5
Straight-line amortization of multi-	-client library						65.3
Produced accelerated amortizatio	on of multi-client library						49.5
Impairment of the multi-client libra	ary						1.3
Operating profit (EBIT)							104.4
Organic multi-client investments							129.4

Multi-Client

Marine Data Acquisition

■ Contract ■ Multi-client

^<sup>1Wherof approximately eight percentage points were used for NES.

Imaging and NES

License Round Activity

N O R T H A M E R I C A

Canada – Labrador & Jeanne d'Arc:

• Call for Nominations Open
• Expect Call for Bids Nov 2025 (close)

US GOA:

• Lease Sale planned for 10 December 2025

US Onshore:

• Alaska North Slope Lease Sale Close Nov 2025
• BLM lease sales in MT, NM, WY in Q4 2025

L A T I N A M E R I C A

Brazil:

• Permanent Offer 5 2024 (closed)
• Permanent Offer 6 2025 (open round)

Trinidad:

• Deep Water Round – Q4 2024 (open)

Argentina:

• Offshore Round 2 – 2024 (open)

E U R O P E

Norway:

• 2025 APA Round Q3 2025 (deadline)
• 26th Round Q4 2025 (nominations)

A F R I C A / E A S T M E D

Angola:

• 2025 round 10 blocks
• Permanent Offer Blocks available for direct negotiation
• MOU exclusive study available prenegotiated

Congo-Brazzaville

• 2025 license round planned

Cote d'Ivoire

• Open door

Egypt:

• EGAS 2024 International Bid Round Gabon:
• Open Door

Ghana:

• Open Door for available blocks

Lebanon:

• Ongoing license round

Liberia:

• 2 nd time-limited license round Q4 2025

Libya:

• Licensing round announced Q1 2025

Nigeria:

• 2025 License round planned

Madagascar

• 2025 license round planned

Tanzania

• 2025 license round

Somalia:

• Direct awards

Togo

• 2025 license round planned

A S I A - P A C I F I C

India:

• Open Acreage Licensing Policy OALP launched in February (25 blocks offered in total, of which 19 are offshore)

Indonesia:

• Open door policy (JSA mechanism)

Malaysia:

• 2025 MBR – Feb 2025 (open) to Sep 2025 (close)