IBM has acquired Kenexa for US$1.3bn as the company further consolidates the human resource management software market.

After rivals SAP bought SuccessFactors for $3.4bn and Oracle bought Taleo Corp $1.9bn within the past year, IBM says the purchase will help the company bring data and expertise into the hands of business leaders within sales and marketing, product development and HR.

"The Kenexa acquisition will complement IBM's social business and HR business services leadership," IBM says.

"As a result of this synergy, clients will be able to attract and develop the right skills to build the right team.

"Every company, across every business operation, is looking to tap into the power of social networking to transform the way they work, collaborate and out innovate their competitors.”

IBM's $46 per share offer represented a 42.5% premium to Kenexa's close on Friday, with company shares in the software provider jumping close to 42% $45.75 in early trading on the New York Stock Exchange.

IBM confirmed they expect the transaction to close in the fourth quarter.