LONDON (Reuters) - Britain's top share index fell slightly on Tuesday, with Standard Chartered (>> Standard Chartered PLC) and BP (>> BP plc) leading the broader market lower after their results failed to impress investors.

Standard Chartered dropped 5.4 percent, the top faller on the blue-chip FTSE 100 <.FTSE>, after the bank reported a decline in third quarter income and warned of compliance troubles ahead.

Oil major BP (>> BP plc) dropped 4.5 percent after reporting a fall in third-quarter earnings. Underlying replacement cost profit, its equivalent of net income, fell to $933 million (£761.88 million) from $1.8 billion (£1.47 billion) a year earlier.

"This is the ninth consecutive quarter of decline in BP's earnings, and it is hard to see the end of the tunnel given the challenging dynamics in the oil market," said Ipek Ozkardeskaya, analyst at London Capital Group.

In contrast, shares in Royal Dutch Shell rose 3.8 percent, among the top FTSE gainers, after reporting an 18 percent rise in underlying net profit, beating forecasts.

The FTSE 100 index was down 0.5 percent at 6,917.14 points at its close. The index is up more than 10 percent so far this year.

Britain's mid-cap FTSE 250 index <.FTMC> closed 0.1 percent lower.

Weir Group (>> Weir Group PLC) fell 2.4 percent after the pipe and valve maker trimmed its 2016 profit forecast due to weaker downstream oil and gas markets and tougher conditions in the Middle East.

Precious metals miners Polymetal International (>> Polymetal International PLC) and Fresnillo (>> Fresnillo Plc) jumped 5.3 percent and 4.8 percent respectively, the top gainers on the mid-cap index after the price of gold hit a one-month high on uncertainty about the outcome of the U.S. presidential election.

Price comparison site Moneysupermarket.com (>> Moneysupermarket.Com Group PLC) rose more than 10 percent after saying that growth in sales of insurance helped third-quarter revenue rise 12 percent, giving it confidence in its outcome for the year.

(Reporting by Atul Prakash; Editing by Richard Balmforth and John Stonestreet)

By Kit Rees and Atul Prakash