NICOSIA (Reuters) - Cyprus's socialist party said on Tuesday it would not throw its support behind either remaining candidate in a runoff vote on February 24, closely watched by investors as the cash-starved island teeters on the brink of default.

The vote will pit Nicos Anastasiades, a conservative candidate in favor of a swift bailout deal with international lenders, against Communist-backed Stavros Malas, who supports a bailout but with fewer austerity measures.

"The positions (of the party) ... do not permit it to position itself in favor of a candidate in the second round of the presidential elections," Demetris Papadakis, spokesman for the Socialist EDEK party, said.

He said it was a unanimous proposal to be made to the decision-making body of the party scheduled to meet on Thursday.

Anastasiades has an 18-point lead over Malas and remains the firm favourite.

EDEK had supported George Lillikas, an independent who came third in the first round of voting on February 17, polling 25 percent of the vote.

(Reporting By Michele Kambas; Editing by Michael Roddy)