"We're delighted with Deutsche Post's decision to become our principal investor," said Williams Lea chief executive Tim Griffiths (pictured). "With their backing we are confident that we will be able to satisfy even larger and more complex business process outsourcing requirements for our clients on a truly global scale."

The offer by the German mail and logistics company follows months of speculation that the print management and facilities group was up for sale.

Private equity house 3i divested its 38% stakeholding for 110m.

DPWN expects to purchase the remaining stake in Williams Lea in the next three years.

With the acquisition of Williams Lea, DPWN, which includes DHL Global Mail, said it would strengthen its presence in the global mail market.

The transaction, subject to regulatory approval, is expected to be completed in March.

The deal comes less than a year since fellow UK BPO innovator Astron was snapped up in a $1bn deal by RR Donnelley.

Williams Lea employs 6,500 staff worldwide and achieved sales of 444m in 2005. Its clients include Norwich Union, O2, BMW, Prudential, AXA and Debenhams.