NEW YORK, Aug. 30, 2011 /PRNewswire/ -- ACI Worldwide, Inc. (Nasdaq: ACIW), a leading international provider of payment systems, today announced that it is commencing an exchange offer to acquire all of the outstanding shares of S1 Corporation (Nasdaq: 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 "SEC"). "While it remains our strong preference to enter into a negotiated transaction with S1, we believe taking our premium cash and stock offer directly to S1's shareholders is the best way to advance this compelling combination," said Philip G. Heasley, President and Chief Executive Officer of ACI. "We believe that ACI's enhanced proposal is clearly superior to and provides S1 shareholders with far greater value than the Fundtech transaction. We remain resolute in our commitment to take the steps necessary to complete this transaction." On August 25, 2011, ACI enhanced its July 26, 2011 proposal to acquire all of the outstanding shares of S1 in a negotiated merger transaction by increasing the cash component of its proposal from $5.70 per share to $6.20 per share. Details of the Exchange Offer 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. ACI has secured committed financing from Wells Fargo Bank, N.A. for the cash portion of the transaction. The exchange offer is expected to expire at 5:00 p.m. Eastern Time on September 28, 2011, unless extended. Shareholder questions regarding the exchange offer or requests for offering documents should be directed to ACI's Information Agent for the exchange offer, Innisfree M&A Incorporated, toll-free at (888) 750-5834. Offering materials are also available on the SEC's website at www.sec.gov. S1 shareholders are urged to read the offering materials filed by ACI, which contain important information about the exchange offer. Solicitation Against Proposed Fundtech Transaction As previously announced on August 25, 2011, ACI has filed definitive proxy materials with the SEC in connection with the solicitation of votes against proposals related to the proposed merger of S1 and Fundtech. ACI urges shareholders to vote the BLUE proxy card AGAINST the Fundtech transaction today. S1 shareholders are encouraged to read the definitive proxy materials in their entirety as they provide, among other things, a detailed discussion of ACI's superior proposal and the reasons behind the ACI recommendation that shareholders vote AGAINST the proposed Fundtech transaction. Wells Fargo Securities is serving as financial advisor to ACI and Jones Day is serving as its legal advisor.