Britain's FTSE regains traction as oil steadies

* FTSE 100 up 0.3 pct

* Oil majors higher as Brent steadies

* Wood Group reassures with BP contract win

* Ex-divs weigh on the market

By Alistair Smout

LONDON, Dec 11 (Reuters) - Britain's top share index edged higher on Thursday, after a three-session losing streak pushed it to its lowest levels in over a month, with major oil firms picking up after a sell-off.

The FTSE 100 was up 18.81 points, or 0.3 percent, at 6,518.86 by 0835 GMT after setting its lowest close since Nov. 4 on Wednesday.

The index had fallen 3.6 percent in the first three sessions of this week, hit in part by a slumping oil price, which knocked heavily-weighted energy stocks.

Brent crude ticked higher on Thursday, lifting oil and gas shares, although it remained below $65 per barrel, not far from the previous session's five-year low.

A global glut and weak data from China have put renewed pressure on oil prices this week.

Tullow Oil (LSE: TLW.L - news) , Royal Dutch Shell (Xetra: R6C1.DE - news) and BP were 1.7-2 percent higher.

Mid-cap energy services firm John Wood Group rose 3.6 percent after it said it had secured a $750 million, five-year contract from BP, and said earnings would be in line with expectations.

The energy services sector has been hit by concerns that such contracts could dry up as oil majors cut back further on capital expenditure in the face of a weak oil price. Blue chip peer Petrofac rose 1.7 percent.

"Wood Group are a solid company and their message today is encouraging," Mark Ward, head of execution trading at Sanlam Securities, said.

"I think they are still undervalued here; they are still nearly 250 pence from their mid-year highs back in June. Clearly the weak oil price will be an ongoing concern, but they are a strong company who can ride out the volatility."

Oil and gas-related stocks were the best performers, adding 14.5 points to the FTSE index.

Elsewhere, insurer Legal & General (LSE: LGEN.L - news) rose 1.1 percent, with traders citing an upgrade to "buy" from "neutral" by Nomura as being behind the move.

Aberdeen Asset Management (Other OTC: ABDNF - news) , 3I Group and Babcock were 1-2.4 percent lower as they traded without entitlement to their latest dividend payouts. (Reporting by Alistair Smout; Editing by Susan Fenton)