Social Democrat Justice Minister Jose Meneres Pimentel, 53, has been nominated to take over from outgoing Prime Minister Francisco Pinto Balsemao in a bid to reunite Portugal's fractured government coalition, political sources said late today.

Social Democratic spokesmen refused official comment on the reports, but sources close to the party said Balsemao would propose Meneres Pimentel as his successor in a meeting with President Antonio Ramalho Eanes on Wednesday.

Meneres Pimentel, a lawyer and former provincial public prosecutor, is seen as a moderator capable of bringing together the warring liberal and conservative factions in the ruling Democratic Alliance of Social Democrats and Christian Democrats.

He played a key role in negotiating Balsemao's immediate return to office when the Social Democrat leader first resigned in August 1981 in an attempt to silence hard-line dissidents within the party.

Balsemao made it clear he was quitting for good when he stepped down on Sunday under pressure from the same right-wing critics who attacked his leadership as weak in contrast to the confrontation politics of his predecessor, Francisco sa Carneiro, killed in an air crash in December 1981.

Balsemao's resignation was precipitated by a swing to the Socialist opposition in municipal elections.