UPDATE 1-Trans Alaska oil shipping below average rates

(Adds quote from operator, details)

NEW YORK, July 2 (Reuters) - The Trans Alaska Pipeline System was still shipping crude well below the average 2009 rate this week, after routine maintenance in mid-June, the operator said Thursday.

The system was carrying about 551,000 barrels per day of crude during the 24-hour period ending Thursday, said a spokeswoman for Alyeska, which operates the line. That was about 23 percent below the year-to-date average of about 714,000 bpd.

The relatively weak stream of crude helped push U.S. oil inventories down more than expected last week, according to the U.S. Energy Information Administration.

Alyeska had shut the pipeline starting on June 20 for 36 hours of routine maintenance.

It normally takes the line a while to recover to full volumes after maintenance. But spokeswoman Michelle Egan said "a fair amount of work" was still being done by Alaskan crude oil producers, which also has helped keep the rate low.

The pipeline shutdowns are coordinated with North Slope oil producers' summer maintenance plans.

Alyeska, a consortium owned by BP Plc (BP.L: Quote, Profile, Research), ConocoPhillips (COP.N: Quote, Profile, Research), ExxonMobil (XOM.N: Quote, Profile, Research), Unocal Pipeline Co and Koch Alaska Pipeline Co, typically conducts one or two line-wide maintenance shutdowns each summer.

The spokeswoman said Alyeska should be able to make up for the lost volumes by sending about about 750,000 bpd down the line later in the summer. However, Alyeska also said another, similar maintenance process on the pipeline is slated for July 18 to 19.