Irvine-based Epicor Software, the developer of enterprise business software, said today that it has agreed to be acquired by private equity firm apax Partners, in a deal worth approximately $976M. Epicor said Apax will acquire all of its common stock for $12.50 per share in cash. The offer is a premium of 11.2 percent over Friday's close of Epicor stock. As part of the acquisition, Epicor said it is acquiring Activant Solutions, a provider of business management software whichi s backed by Hellman & Friedman, Thoma Bravo and JMI Equity. Financial terms of that acquisition were not announced. Epicor said the combined buyout and acquisition will create a firm with $825 million in annual revenues.