ATK Announces Right to Convert 2.75% Convertible Senior Subordinated Notes due 2011

ATK ATK today announced that holders of the 2.75% Convertible Senior Subordinated Notes due 2011 are entitled to convert their Notes into shares of the Company's common stock at any time between August 15, 2011 and the close of business on September 14, 2011, which is the business day immediately preceding the stated maturity of the Notes of September 15, 2011 The conversion rate of the Notes as of the date hereof is 10.4208 shares of the Company's common stock per $1,000 principal amount of the Notes (a Conversion Price of $95.96). The Company will settle in cash 100% of the Conversion Obligation in respect of the principal amount of Notes that are converted, and will settle any remaining portion of such Conversion Obligation in shares of common stock.