"My visit came to reach a political reconciliation and to sign the Gulf initiative" by which President Ali Abdullah Saleh will step down in return for immunity from prosecution for himself and his family, Benomar told reporters upon his arrival.
Saleh has come under domestic pressure to step down in terms with a UN roadmap which calls on him to hand over power to his deputy Abdrabuh Mansur Hadi, who will lead a two-year-long transitional period.
The interim period would see the formation of a reconciliation government, the restructuring of military bodies, and the drafting of a constitution, according to Yassin Saeed Noman, leader of the Common Forum which groups parliamentary opposition parties.
The roadmap, drawn up in two weeks of talks in July held by Benomar in Yemen with the opposition and leading figures of the ruling party, provides an implementation mechanism for the Gulf-brokered plan which Saleh has stalled for months.
"We are ready and it is up to the president to take the decision to sign the Gulf initiative" which was already signed by the opposition, Noman told AFP.
But the opposition is worried by Saleh's "manoeuvres," said Noman.
The spokesman for the ruling General People's Congress party, Tariq al-Shami, told AFP that "the president has already made up his mind on the plan and its implementation mechanism."
But with Benomar's visit, "we are waiting to reach an agreement with the opposition on outstanding issues," said Shami.
"We have responded positively to all matters raised by the opposition. However, there are certain details which must still be worked out with the opposition," he added, with which he called for dialogue -- a proposal the opposition has repeatedly rejected before Saleh steps down.
For the opposition, "there are no outstanding issues on the implementation mechanism," Noman said, urging Saleh to sign the agreement "to end the current political deadlock."
Noman said that a delegation from the opposition will, over the weekend, go to Saudi Arabia, a key role player in the region, in response to an invitation by Saudi Foreign Minister Prince Saud al-Faisal.
The delegation will also visit Egypt and China, he said.
Meanwhile, one man was killed and nine other people were wounded in the flashpoint city of Taez, said medics, while in the capital Sanaa three people were wounded as protesters took to the streets calling for Saleh to face international justice.
Witnesses said Republican Guard troops, commanded by Saleh's son Ahmed, fired artillery rounds into the centre of Taez where tens of thousands of protesters were calling for the veteran leader's prosecution.
In Sanaa, armed civilians opened fire on a similar demonstration, wounding three people, witnesses and medics there said.
"No immunity, no guarantee, Saleh must be tried with his regime," chanted the protesters as they marched on central Sanaa. "World, UN Security Council: Saleh is a war criminal."
The protesters were met with live rounds fired on them from a building as they neared the capital's centre, witnesses told AFP.
Saleh's opponents announced on Friday the creation of a "legal committee" to gather evidence and witness reports from citizens on "the crimes of Saleh and the remnants of his regime" to present to the International Criminal Court.
Following Benomar's last visit, the UN Security Council adopted a resolution strongly condemning deadly government attacks on demonstrators and backed the Gulf plan.
Saleh, who had "welcomed" the resolution, has repeatedly stalled the Gulf initiative aimed at ending months of protests. Under the plan he will step down 30 days after it is signed in exchange for immunity from prosecution.
The Security Council had called on Saleh to keep a promise to immediately sign the plan and for a peaceful power transition "without further delay."
Several hundred people have been killed since protests against the president began.