OLIN Corp — Director's Dealing 2011

May 5, 2011

SEC Form 3 — Initial Statement of Beneficial Ownership

Issuer: OLIN CORP (OLN)
CIK: 0000074303
Period of Report: 2011-04-28

Reporting Person: Chirumbole Frank W (President, Chlor Alkali Prod.)

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock $1 par value	13548	Direct
Common Stock $1 par value	712.0563	Indirect

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Employee Stock Option (right to buy)	$16.10	2012-02-13	Common Stock (12000)		Direct
Employee Stock Option (right to buy)	$18.52	2014-02-11	Common Stock (9200)		Direct
Employee Stock Option (right to buy)	$23.78	2015-02-09	Common Stock (9200)		Direct
Employee Stock Option (right to buy)	$20.68	2016-02-08	Common Stock (11775)		Direct
Employee Stock Option (right to buy)	$16.52	2017-02-12	Common Stock (10250)		Direct
Employee Stock Option (right to buy)	$20.29	2018-02-06	Common Stock (7500)		Direct
Employee Stock Option (right to buy)	$14.28	2019-02-05	Common Stock (12500)		Direct
Employee Stock Option (right to buy)	$15.68	2020-02-04	Common Stock (12500)		Direct
Employee Stock Option (right to buy)	$18.78	2021-02-11	Common Stock (14000)		Direct
Restricted Stock Units	$		Common Stock (3333)		Direct
Restricted Stock Units	$		Common Stock (3333)		Direct

Footnotes

F1: The figure shown represents shares of Olin Common Stock held under the Olin Common Stock Fund of the Olin Corporation Contributing Employee Ownership Plan (CEOP), a tax-conditioned plan reflecting transactions exempt under Rule 16b-3, as reported by the Plan Administrator as of April 28, 2011.

F2: Option vests in three annual installments beginning on 2/5/2010.

F3: Option vests in three annual installments beginning on 2/5/2011.

F4: Option vests in three annual installments beginning on 2/11/2012.

F5: Right to acquire shares of common stock vesting on 2/5/2012.

F6: Security converts on a one-for-one basis.

F7: Right to acquire shares of common stock vesting on 2/5/2013.