UPDATE 6-Brent crude choppy on pipeline restart, US crude rises

* Brent oil pipeline start-up curbs Brent prices

* U.S. jobless claims fall unexpectedly

* Coming up: China data, U.S. February jobs report Friday

(Recasts with updated prices, market activity; changes dateline, pvs LONDON)

NEW YORK, March 7 (Reuters) - Brent crude futures see-sawed on Thursday as the restart of the Brent pipeline system in the British North Sea curbed gains, while U.S. crude received a lift from a weaker dollar and supportive jobless claims data.

The Brent oil pipeline system in the British North Sea began a restart process after Saturday's second shutdown in almost two months. A spokesman for Abu Dhabi-based pipeline operator TAQA confirmed the restart had begun, but added that it would take time before crude started flowing again.

The euro rose after the European Central Bank left its benchmark interest rate unchanged and on support from healthy demand at a Spanish debt auction that eased some investor concern about the euro zone. The dollar index weakened despite the U.S. currency's strength versus the yen.

U.S. initial claims for unemployment benefits fell unexpectedly last week, lending support to crude prices and equities on Wall Street.

"There is a little pressure coming from the restart of Brent, but it seems the market is holding above $110 pretty well," said Christopher Bellew, a broker at Jefferies Bache in London.

Brent April crude dipped 10 cents to $110.96 a barrel by 11:45 a.m. EST (1645 GMT), having swung from $110.45 to $111.40.

U.S. April crude was up 77 cents at $91.20 a barrel, having traded from $90.22 to $91.73.

Brent's premium to U.S. crude <CL-LCO1=R> hovered below $20 a barrel, but it moved from $19.38 to $20.73 during the session.

Oil came under pressure on Wednesday after a U.S. government report showed that domestic crude inventories rose by 3.83 million barrels, much more than the 500,000-barrel increase expected in a Reuters poll of analysts.

Market participants awaited February trade data from China scheduled for release on Friday, including crude demand numbers, and the U.S. February non-farm payrolls report that will follow at 8:30 a.m. EST (1330 GMT).

"We have a busy end of the week as far as macroeconomic data is concerned; the oil markets are watching out for those," said Ben le Brun, an analyst at OptionsXpress in Sydney.

(Reporting by Robert Gibbons in New York, Alex Lawler in London and Ramya Venugopal in Singapore)