A man watches a televised speech of President Pervez Musharraf to the nation in Islamabad August 18, 2008. Musharraf announced his resignation on Monday in the face of an impending impeachment motion by the ruling coalition government. [Agencies]

Pakistan's beleaguered President Pervez Musharraf announced his resignation on Monday in the face of an impending impeachment motion by the ruling coalition government.

The former army chief and firm US ally has seen his popularity slide over the past 18 months and has been isolated since his allies lost a February election.

"After consultations with legal advisers and close political supporters and on their advice, I'm taking the decision of resigning," Musharraf said a televised address.

"My resignation will go to the speaker of the National Assembly today."

The coalition government, led by the party of assassinated former prime minister Benazir Bhutto, said on August 8 it planned to impeach Musharraf.

The powerful army has publicly kept out of the controversy over its old boss.

No unrest was expected as a result of the increasingly unpopular leader's resignation.

Investors in Pakistan's financial markets -- while appreciating Musharraf's investor-friendly rule which, until this year, saw strong growth and surging stocks -- were expected to welcome his resignation as heralding an end to political uncertainty.

Pakistani stocks rose 4 percent on the announcement.

Prolonged jockeying and uncertainty over Musharraf's position has hurt Pakistan's financial markets and raised concern in Washington and among other allies it is distracting from efforts to control violent militants in the nuclear-armed nation.

The ruling coalition had prepared impeachment charges against Musharraf focusing on violation of the constitution and misconduct.

Coalition officials had hoped Musharraf would quit to avoid impeachment while some allies have said he should at least answer charges brought against him before stepping down.

Officials from Saudi Arabia, as well as the United States and Britain, have been involved in negotiations aimed at ending the confrontation between Musharraf and the government.

The United States, which has relied on Musharraf for Pakistani cooperation in its campaign against terrorism, had said the question of Musharraf's future was for Pakistanis to decide.

US Secretary of State Condoleezza Rice said on Sunday that Musharraf has been a "good ally," but she declined to say whether he would receive US asylum if he stepped down.

"This is an issue that is not on the table," Rice said in an interview with Fox News.

Musharraf seized power in a 1999 coup but has been isolated since his allies lost a February election.

All four provincial assemblies passed resolutions in recent days pressing him to resign and several old allies have joined the campaign against him.