Libyan rebels pressed the regime of Col. Moammar Gadhafi Sunday, taking control of a key city near the capital of Tripoli, declaring a provisional government and allowing oil shipments to resume from territory under their control.

An oil tanker was expected to depart the port of Tobruk in the northeast corner of Libya sometime Sunday night carrying 700,000 barrels of oil, said Hassan Bulifa, a member of the management committee of Arabian Gulf Oil Co., Libya's largest oil producer and the only oil company based in the country's...