S1 Corporation Issues Statement Regarding Unsolicited Proposal From ACI Worldwide

S1 Corporation (Nasdaq: SONE) today announced that it has received a letter dated July 26, 2011 from ACI Worldwide, Inc. (Nasdaq: ACIW) outlining an unsolicited proposal to acquire S1 Corporation for $9.50 per share in a mix of cash and common stock of ACI.

As previously announced, on June 26, 2011, S1 and Fundtech Ltd. (Nasdaq: FNDT) executed a merger agreement, which provides for the combination of the two companies. S1 continues to be bound by the terms of the merger agreement with Fundtech.

S1's Board of Directors will review the terms of the proposal submitted by ACI in a manner consistent with its obligations under the merger agreement with Fundtech and applicable Delaware law.