The deal, which is worth $6.4bn (£4bn) in a cash and stock transaction, is expected to triple Xerox's service revenues from $3.5bn in 2008 to around $10bn next year.

According to Ursula Burns, chief executive officer at Xerox, the acquisition couples strength in document technology with the expertise in managing and automating work processes of ACS.

"Acquiring ACS helps us expand our business and benefit from stronger revenue and earnings growth," she said.

The deal means Xerox will become a $22bn turnover company, with $17bn of such revenues recurring, according to Burns.

Following completion of the transaction, which is expected to conclude in the first quarter of 2010, ACS will continue to operate as an independent company.

Lynn Blodgett, president and chief executive of ACS, said: "We’re proud of our significant profitable growth over the past 20 years and our ability to manage our clients’ operations with a global infrastructure and workforce.

"We also know that for ACS to expand globally and differentiate our offerings through technology, we need a partner with tremendous brand strength and leading innovation."