KUALA LUMPUR (Reuters) - Malaysia's main ruling party will postpone a leadership vote until March of next year and Prime Minister Abdullah Ahmad Badawi said he would step down earlier than the planned 2010, but did not say when.

Abdullah, the leader of the country's main coalition party, the United Malays National Organization (UMNO), had planned to hand over to Deputy Prime Minister Najib Razak, the son of Malaysia's second premier.

"Since we have decided to speed up the transition, the original 2010 deadline is out of the question," Abdullah told a news conference after a meeting of the governing body of UMNO.

Abdullah has come under pressure since the Barisan Nasional coalition, in which UMNO is the biggest party, stumbled to its worst election result in March this year.

UMNO, which is part of a coalition of ethnic-based parties, is under pressure from opposition leader Anwar Ibrahim who says he has won over sufficient government MPs to join his alliance so that he can become prime minister.

UMNO has led the coalition that has ruled Malaysia for 51 years and its leader by tradition becomes prime minister at the head of the Barisan Nasional government, a 13-party alliance.

A leadership vote had been due in December.