PGS ASA — Major Shareholding Notification 2010

May 26, 2010

Disclosure of shareholding

General Shareholder Disclosure Obligations under the

Norwegian Securities Trading Act of 29 June 2007 No 75

1. Issuer: Petroleum Geo-Services ASA

2. Date when the threshold was reached or passed: May

25th, 2010

3. Date on which the notification duty arose (if

other than in 2 above):

4. Name of the person obliged to notify, and, if

voting rights are separated from the ownership of

shares, the name of the shareholder:

AllianceBernstein L.P.

Address: 1345 Avenue of the Americas

Postal code: NY 10105

Residence: New York

Country: USA

5. Name and qualification of the signatory: Hinde

Idrissi - Compliance

6. Number of shares/rights to shares encompassed by

the notification: 10,051,093

Number of voting rights encompassed by the

notification: 10,051,093

7. Percentage and number of shares and voting rights

now held by the notifying entity and its Close

Associates (if any):

Person obliged

to notify NUMBER OF SHARES % OF SHARES

RIGHTS TO SHARES % OF RIGHTS TO SHARES

NUMBER OF VOTING RIGHTS % OF VOTING RIGHTS

AllianceBernstein 10,051,093 5.07% 0

0 10,051,093 5.07%

TOTAL 10,051,093 5.07% 0 0

10,051,093 5.07%

8. Event that triggered the notification

(acquisition, subscription, sale, "passive" crossing

etc). If the event that triggered the notification

was related to a Close Associate of the notifying

entity, please specify: Acquisition of voting shares

9. If the event that triggered the notification was

related to a Close Associate, please specify the

relationship between the notifying entity and the

Close Associate in full:

10. If the notification comprises rights to shares,

please describe the rights as well as when the rights

can be exercised/time to maturity. Please also state

whether the rights are to existing shares or a right

to subscribe for new shares:

Date: May 26th, 2010

Place: Paris - France