The move comes after Syrian forces killed more than 200 people in a Damascus suburb and carried out mass arrests as residents tried to bury the bodies, rebel activists said.
The death toll likely would reach 250, the opposition Syrian Observatory for Human Rights said, while the opposition Local Coordination Committees of Syria said Monday it documented 386 deaths by army soldiers and loyalist militias in the town of Jdaidet al-Fadl.
With the sanctions action, EU countries can engage in importing of oil and petroleum products as well as investment in and exports of technology to the Syrian oil industry, a Council of the European Union news release said.
It added consultation with the Syrian National Coalition for Opposition and Revolutionary Forces will be required, to ensure transactions don't circumvent EU sanctions against Syria, in particular asset freezes on those associated with repression.
The import ban on Syrian oil and petroleum was imposed in September 2011.
The announcement easing the sanctions came days after the Syrian government was accused by rebel leaders of carrying out the massacre and mass arrests in Jdaidet al-Fali, beginning Friday, activist Shamel al-Jonali told The New York Times.
Hundreds of people were arrested and taken to a nearby military base, he said. Some of those arrested were released but others were found dead, Jonali said.
The campaign by the regime of President Bashar Assad, which continued into Monday, involved burning houses, arresting men, taking over field hospitals and killing people who were wounded, activists said.
The state-run Syrian Arab News Agency gave a different account.
"Armed forces units inflicted heavy losses on terrorists in the town of Jdaidet al-Fadl and destroyed weapons and ammunition and killed and wounded members of the terrorist groups," it said.
The SANA report, monitored by United Press International, gave no death toll. It was accompanied by photos of bodies lying in rubble next to assault rifles. The bodies were wearing what looked like paramilitary battledress.
Video images activists posted online appeared to show a row of bloodied bodies wrapped in carpeting or bags. Several bodies showed signs of being shot in the face. Most were men but a few appeared to be children.
The Syrian Revolutionary General Command and Local Coordination Committees said women also were among the dead.
None of the information about the events could be independently confirmed.
Fighting in the area has stepped up in recent months as weapons were sent from Jordan to rebel groups with U.S. assistance, the Times said.
U.S. Secretary of State John Kerry said Sunday Washington would double its non-lethal aid to the Syrian opposition, providing $123 million in fresh assistance.