ACI Worldwide Commences Exchange Offer for S1 Stock

ACI Worldwide, Inc. ACIW today announced that it is commencing an exchange offer to acquire all of the outstanding shares of S1 Corporation SONE common stock. Under the terms of the exchange offer, S1 shareholders would receive $6.20 in cash and 0.1064 ACI shares for each share of S1 they hold, assuming full proration, which as of August 29, 2011, had a blended value of $9.44 per share. The complete terms and conditions of the exchange offer will be set forth in the prospectus/offer to exchange on Form S-4 that ACI expects to file today with the Securities and Exchange Commission . The prospectus/offer to exchange fully details the terms and conditions of the offer. As described in the prospectus/offer to exchange, S1 shareholders will be able to elect to receive $10 per share in cash or 0.2800 shares of ACI common stock for each S1 share they hold. This election will be subject to a maximum of 62% of S1 shares exchanging for cash and 38% of S1 shares exchanging into ACI common stock, with any oversubscription subject to proration. Based upon the price of ACI common shares on August 29, 2011, the value of the cash component of the offer exceeds the value of the stock component of the offer.