BERLIN (AFP) - Germany's SAP, a software company specialising in human resources functions, on Saturday announced it was to acquire US company SuccessFactors for $3.4 billion. Under the deal, an American subsidiary will pay $40 per share in cash for SuccessFactors, 52 percent more than the closing stock price on Friday, a statement said. The deal is the latest development in the growing rivalry between SAP and competitor Oracle.