The national ban on oil exports was repealed last December.
In July and early August, two Bahamas-flagged tankers, the Tianlong Spirit and the Cascade Spirit, departed Valdez en route to foreign ports. The second foreign vessel to pick up Alaska North Slope crude, the Cascade Spirit, left Valdez Aug. 6.
A BP spokeswoman said the vessels were chartered and the oil was exported because of a scheduled dry-docking of another tanker and maintenance activities at West Coast refineries that are the typical landing place for Alaska oil.
The domestic shipments from Alaska require American-built and crewed tankers by Americans to comply with the Jones Act, and the vessels and crews that call on Valdez are typically longstanding, repeat customers, according to U.S. Coast Guard officials.