UPDATE 4-Sharif's party quits Pakistan government

(Adds Commonwealth re-admitting Pakistan)

By Kamran Haider

ISLAMABAD, May 12 (Reuters) - Former prime minister Nawaz Sharif pulled his party out of Pakistan's six-week-old coalition government on Monday, plunging the volatile Muslim nation back into political uncertainty.

Sharif, whose Pakistan Muslim League (Nawaz) was the second-largest member of a four-party alliance, made the announcement after failing to break a deadlock with its main coalition partner over the reinstatement of dismissed judges.

Sharif made the restoration of 60 judges sacked by President Pervez Musharraf in November the main condition for joining the coalition led by the party of Asif Ali Zardari, the widower and political successor of the late Benazir Bhutto.

Three days of talks in London between Sharif and Zardari, whose Pakistan People's Party (PPP) leads the coalition, ended on Sunday without any breakthrough.

"Our ministers will meet the prime minister tomorrow and will submit their resignations," Sharif told a news conference.

Nine of the 24 ministers in Prime Minister Yousaf Raza Gilani's cabinet belong to the PML-N, including Finance Minister Ishaq Dar, who was due to present the annual budget in weeks with the country sliding deeper into economic problems.

Sharif, who submitted his nomination papers to contest a by-election due in late June, said his party would continue to support the PPP government despite quitting the cabinet.