UPDATE 4-Bhutto party announces candidate for Pakistani PM

(Adds comment from Gilani)

By Augustine Anthony

ISLAMABAD, March 22 (Reuters) - The party of assassinated former Pakistani prime minister Benazir Bhutto nominated on Saturday former National Assembly speaker Yousaf Raza Gilani as its candidate for prime minister.

President Pervez Musharraf has asked the National Assembly to reconvene on Monday to elect the prime minister.

Gilani, a vice chairman of Bhutto's Pakistan People's Party, is all but guaranteed to win the vote with the support of his party, which won the most seats in a Feb. 18 parliamentary election, and its coalition allies.

The PPP is led by Bhutto's widower, Asif Ali Zardari, but he is ineligible to stand for prime minister because he is not a member of parliament.

"At this point, I only urge the nation and you all to pray for me, that we take on such a big challenge and do something for the nation, practically," Gilani told Geo Television shortly after the announcement.

Announcing Gilani would be the party's candidate, PPP spokesman Farhatullah Babar told reporters a consensus had been reached within the party and with its coalition partners.

Party officials said earlier the chairman of the party, the son of Bhutto and Zardari, Bilawal Bhutto Zardari, had been due to announce the candidate but they later said he was feeling unwell.