Blackstone Group LP has agreed that annual payments of $325 million (£230.8 million) would be made for 30 years to the Reuters News business as part of an offer by the U.S. private equity firm to buy 55 percent-stake in Thomson Reuters’ Financial and Risk unit.

Under the terms of the deal, Thomson Reuters will retain a 45 percent stake in the F&R business as part of a partnership with the U.S. buyout firm.

The deal represents the biggest shake-up of Thomson Reuters since it was formed a decade ago by Thomson Corp’s acquisition of Reuters Group. Canada’s Thomson bought London-based Reuters for $17 billion in 2008.

As part of its offer, Blackstone has said the new F&R company would make annual payments of $325 million for 30 years to Reuters News to safeguard that business’s growth prospects.