Spain's Habitat the latest victim of ailing sector

* Spanish property firm Habitat files for administration

* Has debts of 2.3 bln euros

* Colonial says its solvency may depend on asset disposal

* Analysts say may struggle to sell FCC, SFL stakes, Riofisa

(Adds Colonial statement, updates shares to close)

By Andres Gonzalez and Sarah Morris

MADRID (Reuters) - Unlisted Spanish real estate company Habitat filed for administration on Friday with debts of 2.3 billion euros ($3 billion), the second largest default in Spain after fellow property firm Martinsa Fadesa (MFAD.MC).

Spanish property firms have suffered falls of over 30 percent in house sales this year as the real estate sector seizes up in a global financial liquidity squeeze. Martinsa Fadesa filed for administration in July.

The move by Habitat, about 20 percent owned by building group Ferrovial (FER.MC), came after indebted property firm Colonial (COL.MC) said it could be forced into administration if it fails to sell stakes in a number of companies.

Colonial later stressed it was not in insolvency proceedings and its situation had improved since signing an agreement with creditor banks. It made the comments as standard risk statements as enforced by the stock market regulator, Colonial said.

Habitat said property sales would continue as normal and it would work with administrators to reach a deal with creditors.

"Habitat is a viable project which is heavily affected by the current financial-property crisis, but which has high-value assets which support it and give it solidity," Habitat Chairman Bruno Figueras said in a statement.

Habitat said at the end of June it owed 232.3 million euros to La Caixa and 218 million to Caja Madrid, Spain's two largest savings banks, and 190 million to bank BBVA (BBVA.MC).

COLONIAL UNDER PRESSURE

Colonial, Habitat's larger listed rival, said it needed to complete a 1.41 billion euro convertible bond issue and sell subsidiary Riofisa, or a large part of it, together with stakes in builder FCC (FCC.MC) and French group SFL (FLYP.PA).

"If Colonial could not meet the sale obligations described, in the period agreed in the case of Riofisa, the company would not be able to meet its payments on the long-term restructured debt," said Colonial in the prospectus for its bond issue.