RSA a faller as Britain's FTSE dips

* FTSE 100 down 0.3 pct

* Old Mutual gains on strong results

* BP, Anglo American trade ex-dividend

By Liisa Tuhkanen

LONDON, Aug 6 (Reuters) - Britain's top share index edgedlower on Thursday, with insurer RSA a faller after weakresults from a potential bidder reduced prospects of a takeover.

RSA, the subject of interest from Swiss rival ZurichInsurance, dropped 1.5 percent.

"In the short term, we expect RSA to trade based on theprobability of a takeover bid, rather than fundamentalvaluation," Bernstein analysts said in a note. "Hence, onbalance we expect the stock to trade down in the very shortterm."

Other insurers rose, with Old Mutual the top bluechip riser, up 2.7 percent after strong results.

Aviva also benefited from well-received results,adding 1.2 percent after posting forecast-beating half-yearoperating profit, boosted by the ahead-of-schedule integrationof recent purchase Friends Life.

The blue-chip FTSE 100 index was down 0.3 percent at6,732.50 points by 0835 GMT. It gained 1 percent in the previoussession, boosted by better-than-expected results and a reboundin the mining sector.

BP and Anglo American contributed toThursday's falls as they traded without the attraction of theirlatest dividend payouts.

BP was the faller, down 3 percent, while Anglo American shed2.6 percent. The two combined to take nearly 10 points off theindex.

Also in focus for equity investors, the Bank of England isreleasing a slew of data at 1100 GMT, and is likely to revealits policymakers have split over interest rates, adding toexpectations that the central bank is heading for its firstincrease in borrowing costs in nearly a decade. (Reporting by Liisa Tuhkanen, editing by John Stonestreet)

Anglo American

Aviva

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