Yemen's president and opposition agreed on Wednesday to sign a Gulf-brokered deal for a transition of power with slight modifications after intervention from US and European diplomats, an opposition official said.

The deal, which the opposition said would be signed later on Wednesday, would ease entrenched President Ali Abdullah Saleh out of power within a month after a nearly 33-year rule in the impoverished Arabian Peninsula state.

'After American, European and Gulf efforts, there was agreement by the president on the Gulf initiative after simple changes, and the signing will be today,' opposition official Yahya Abu Usbua said.

Al Arabiya television quoted an adviser to the Yemeni president as confirming the signing would take place on Wednesday.

The US and oil giant Saudi Arabia, both targets of foiled attacks from al Qaeda's Yemen wing, are keen to see an end to Yemen's political stalemate, fearing continued chaos could give the militant group more room to operate freely.

Abdullatif al-Zayani, the secretary general of the Gulf Cooperation Council, has been in capital Sanaa since Saturday trying to revive the GCC-brokered deal that Qatar, one of its six members, backed out of citing stalling and 'lack of wisdom'.

Saleh, a shrewd political survivor who has outlasted previous opponents' attempts to challenge his power, indicated in April he would sign the Gulf deal, but refused to put his name to it in the final hours.

He said at the time he would only sign in his capacity as ruling party leader, not as president.

The opposition, whose coalition includes Islamists and leftists, said that among the minor modifications in the deal were changes in who would sign and in what capacity for the opposition and for the government.

'The president will sign for the government in his capacity as president of the republic and as head of the ruling party,' Abu Usbua said.

Protesters, frustrated that three months of street protests have failed to dislodge Saleh, want the 69-year-old leader out immediately and have said they will step up their campaign by marching on government buildings, a move that brought new bloodshed last week as security forces fired to stop them.

Protesters blocked the entrance of the red Sea port of Hudaida, Yemen's second largest port, blocking traffic from entering or leaving, protesters said.

The cities of Ibb, Taiz and Hadramout were brought to a standstill as most workers complied with a strike aimed at pressuring Saleh to leave.-Reuters