Countrywide, which is owned by US buyout fund Apollo management, has been in negotiations about its debt for several weeks.
Earlier in February, creditors put forward a proposal that would see control of the company pass to Oaktree Capital, the American private equity group, in a consortium of private equity investors including Alchemy Partners, Apollo and Polygon.
Slaughter and May corporate partner Gavin Brown and restructuring partner Sarah Paterson have been advising Castle Holdco, the holding company for Countrywide.
Oaktree, which is reported this week to have secured creditor backing for the takeover, turned to Linklaters. Banking partner Yushan Ng was supported by private equity partner Richard Youle and capital markets partner Alexander Naidenov.
Freshfields Bruckhaus Deringer is representing Apollo, with securities partner Don Guiney working alongside US advisers Wachtell Lipton Rosen & Katz US, led by corporate partner Steve Cohen.
Apollo bought Countrywide for £1bn in May 2007 at the height of the property boom.
The proposal put forward by Oaktree and Apollo earlier this month would also cut the company’s debt to £170m and free up £75m in new capital.
The executive management of Countrywide is being advised by Ashurst finance partner James Perry and corporate partner Gavin Gordon.
The directors of Castle Holdco have been receiving separate advice from Halliwells corporate partner Catherine Moss.
White & Case has been instructed by a group of bondholders, who are considering blocking the move.
Finance partner Christopher Kandel said the investors felt the proposal did make adequate provision for the £470m they were owed in senior debt.