UPDATE 1-TransCanada restarts Keystone oil pipeline

* Keystone restarted a day earlier than forecast

* Company expects to meet all May delivery commitments

CALGARY, Alberta, May 13 (Reuters) - TransCanada Corp TRP.TO restarted its 591,000 barrel per day Keystone oil pipeline on Friday, six days after a May 7 spill in a North Dakota pumping station.

The restart came a day earlier than the company, Canada’s No. 1 pipeline firm, had forecast, said James Millar, a spokesman for the company.

The line was shut after a fitting failed within the Ludden pump station, about 65 km (40 miles) southwest of Milnor, North Dakota, spilling about 500 barrels of oil. Most of the oil was contained within the station, though some oil mist drifted onto nearby properties.

A restart of the line, which runs from near Edmonton, Alberta, to Wood River and Patoka, Illinois, and the Cushing, Oklahoma, storage hub, was delayed as TransCanada inspected similar fittings in stations along the route.

Despite the shutdown, TransCanada said it expects to make all its promised deliveries this month.

The line was one of three down because of oil spills. The others are Plains All American Pipeline LP's PAA.N Rainbow pipeline in northern Alberta and Enbridge Inc's ENB.TO Norman Wells pipeline, which extends to the Rainbow line from the Northwest Territories.

TransCanada said 390 barrels of the spilled oil have now been recovered. Most of the clean-up is expected to be finished this weekend. (Reporting by Scott Haggett; editing by Rob Wilson)