UPDATE 5-Martinsa Fadesa to file for administration

(Updates and recasts with company filing for administration, adds LONDON dateline, byline)

By Carlos Ruano and Elena Moya

MADRID/LONDON, July 14 (Reuters) - Spanish property company Martinsa Fadesa (MFAD.MC: Quote, Profile, Research, Stock Buzz) said it would file for administration after it failed to raise funds and meet debt payments, marking one of the biggest corporate failures in the country's history.

Martinsa Fadesa, with 5.4 billion euros ($8.48 billion) of debt, said the move was triggered by its failure to raise a 150 million euro loan -- a requisite of 4 billion euro refinancing agreement earlier this year.

Martinsa Fadesa had asked its 47 creditor banks for the deadline to be extended until Aug. 7.

"Filing for voluntary administration is the best way to avoid aggravating a crisis situation that could become irreversible and have serious repercussions on creditors and all shareholders' interests," the company said in a regulatory filing.

The company added in a statement that it would focus on selling assets to repay creditors, which include Caja Madrid, La Caixa, Ahorro Corporacion and Morgan Stanley (MS.N: Quote, Profile, Research, Stock Buzz).

"The company, along its administrators, will from now on focus in revenue-generating -- through the sale of assets and land management -- and restructuring the company so the project can be revived."

Martinsa Fadesa drew attention to its assets having been valued in June at 10.8 billion euros.