Enbridge Inc. (ENB) and Enterprise Products Partners LP (EPD) said Tuesday they are on schedule to expand the amount of Midwestern crude oil they send to Gulf Coast refiners via their Seaway pipeline.

"Construction of the pump stations will be complete sometime this year or early next year," Enbridge spokesman Larry Springer said. "However, we don't expect that volumes will ramp up to the full capacity until sometime during the first quarter."

Work on the 500-mile pipeline's pump stations should be done by the end of this year but could slip into next year, Springer said. After the work is complete, the amount of oil shipped along Seaway would slowly ramp up from its current 150,000-barrels-a-day capacity as shippers sign on. The companies plan to build an additional line running parallel to Seaway that could handle another 450,000 barrels a day by mid-2014.

"Capacity will begin ramping up to 400,000 barrels a day during the first quarter of 2013," Enterprise spokesman Rick Rainey said.

The two companies reversed Seaway's direction in May so that light, sweet crude oil from Cushing could reach the U.S. Gulf Coast refining belt. Increased U.S. oil production, brought on by advances in drilling technology, had brought oil inventories at Seaway's origin point in Cushing, Okla., to near-record levels.

Seaway's expansion and other projects to bring U.S. crude to the U.S. Gulf would help wean the region off of light, sweet crude imports by the end of 2013, analysts have said.

Write to Ben Lefebvre at ben.lefebvre@dowjones.com

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