ATLANTA – S1 Corp. plans to buy Mosaic Software Holdings Ltd.. The deal brings S1, a global provider of ATM drivers and electronic payment solutions, to its lineup of integrated front-office applications for financial institutions. Mosaic has built a client base of about 210 financial institutions and retailers in more than 40 countries over the past 10 years, including Honda Federal Credit Union, the company says. It has 190 employees, including more than 100 software developers, working in the United States, Australia, South Africa and Great Britain. Atlanta-based S1 has more than 4,000 clients. Mosaic software is used by standard and non-traditional ATM providers as well as for point-of-sale, online retail and Web-based call center payment transactions. Its solutions will be offered separately as well as part of the S1 Enterprise integrated front-office suite, which includes branch, call center, Internet and voice interaction channels. “With the acquisition of Mosaic, S1 is the only vendor in the financial services space that can enable institutions to extend multi-channel integration across all of their primary customer interaction channels,” said Jaime Ellertson, CEO of S1. The deal calls for S1 to pay $37 million in cash and up to $15 million more in earned payments by next May 31.