Quintain Estates has sold a half-share in Wembley's Hilton hotel for £30.1m to Howard Marks' Oaktree Capital.
The 361-room four-star hotel opened last summer. Recent guests include the French women's football team. The half stake has been bought by a company owned by funds managed by Oaktree Capital Management, which the US billionaire set up in 1995.
The Hilton is next to Wembley stadium and the London Designer Outlet, which will open this year with retailers such as Superdry, LK Bennett, Gap and Nike, marking the completion of the first phase of Quintain's regeneration of the area.
The deal helps Quintain towards its target of cutting debts below £400m, and takes the developer's total sales to £185m this year.
Oaktree will receive a preferred return from the joint venture, with Quintain receiving an increasing share of the income when the return has been paid off.
Max James, the chief executive, said: "This transaction clearly reflects the scheme's significant investment potential."