Royal Dutch Shell Plc resumed production at its 100,000-barrel-per-day Perdido deepwater hub in the US Gulf of Mexico on Tuesday, ending a days-long halt caused by an onshore pipeline leak.

Perdido production would return to its usual capacity by late Wednesday.

Shell suspended output on April 9, blaming a subsurface leak in Exxon Mobil Corp's Hoover Offshore Oil Pipeline System (HOOPS), which carries oil from several offshore oilfields to the Quintana Terminal near Freeport, Texas.

Exxon said later on Tuesday that the HOOPS system was not responsible for the leak, but was instead closed following a leak inside the US Department of Energy's Bryan Mound terminal, an oil storage facility connected by several pipelines.

"The cause of the incident is under investigation," Exxon spokesman Todd Spitler said. The HOOPS pipeline has resumed normal operations, he said.

HOOPS also connects the Exxon-operated Hoover, Marshall and Madison offshore oil and gas fields. Production at the Exxon-operated Hoover platform totals about 3,000 barrels per day of liquids, Exxon said.

Perdido is moored in some 8,000 feet of water about 200 miles (321.9 km) south of Galveston, Texas, and is a joint venture among Shell, BP Plc, Arclight Capital Partners and Chevron Corp.