* Ceasefire to allow firefighters to control fuel blaze at airport
* At least 75 bodies found in eastern city of Benghazi
* Fighting worst since the 2011 war that toppled Gaddafi (Adds bodies found in Benghazi)
By Aziz El Yaakoubi and Ayman Al-Warfalli
BENGHAZI/TRIPOLI, July 30 (Reuters) - Rival Libyan militias fighting for control of Tripoli's airport agreed to a temporary ceasefire on Wednesday to allow firefighters to try to control a huge blaze at a fuel depot hit by a rocket.
Meanwhile in Libya's second city, Benghazi, at least 75 bodies, mostly soldiers, were found after two days of fighting in which Islamist fighters and allied militiamen overran an army base.
The past two weeks of fighting have been the worst since the civil war that ousted Muammar Gaddafi in 2011, prompting Western governments to follow the United States and the United Nations in pulling their diplomats out of the North African country.
Two brigades of former rebels, mainly rooted in the towns of Zintan and Misrata, have pounded each other's positions in Tripoli with Grad rockets, artillery fire and cannon, turning the south of the capital into a battlefield.
But except for sporadic shelling away from the ceasefire zone near the international airport, Wednesday was the quietest day in the capital for two weeks.
"Many mediators have succeeded in convincing the militias to stop fighting, at least temporarily," government spokesman Ahmed Lamin said. "They are trying to get them to the negotiating table, we hope they will agree."
France nevertheless closed its embassy on Wednesday, and evacuated 30 French nationals from Tripoli, a few days after the U.S. embassy evacuated its staff across the Tunisian border under heavy military escort.
It was unclear if the blaze at the airport depot, which supplies millions of litres of gasoline and gas to the capital, was under control on Wednesday, although the volume of smoke had lessened.
A spokesman for the state-run National Oil Corporation (NOC), owner of the tanks' operator, Brega Oil company, said he did not yet have any update on the situation.
Three years after the fall of Gaddafi, Libya's government is unable to impose its authority on numerous brigades of former fighters who remain heavily armed and often make political demands of the state.
Benghazi was also quieter on Wednesday, after fierce battles that led special forces to withdraw from the main army base in the city the previous day.
The Libyan Red Crescent's Mohammed al-Misrati said it had found more than 50 bodies inside the base. "We are trying to get them out," he said.
At least 35 of the bodies were later taken to Benghazi's main hospital, according to a Reuters reporter. Sources in the city's hospitals said they had received at least 25 bodies from fighting in other places.
The forces of the self-declared Benghazi Shura Council, which include former rebels and militants from the al Qaeda-linked Ansar al-Sharia, seized the base on Tuesday after fighting involving rockets and warplanes.
Special forces troops and irregular forces loyal to Khalifa Haftar, a renegade former army general who had launched a campaign to clear Benghazi of Islamist militants, withdrew to an air base outside Benghazi, Haftar's spokesman said.
Benghazi's main police station was also abandoned on Wednesday morning, according to a Reuters reporter at the scene.
Fighters from Ansar al-Sharia, classified as a terrorist organisation by Washington, have been blamed by authorities for an attack on the U.S. consulate in Benghazi in 2012 in which the U.S. ambassador was killed. (Editing by Patrick Markey and Kevin Liffey)