Glencore leads Britain's FTSE to seven-month low

* FTSE 100 down 1.9 pct

* Glencore (Xetra: A1JAGV - news) drops after profit fall

* Fellow miners knocked by unease about Chinese economy

* Admiral jumps on forecast-beating results (Updates with closing prices)

By Alistair Smout and Kit Rees

LONDON, Aug 19 (Reuters) - Britain's top share index fell on Wednesday to its lowest level since January, hit by anxiety over top metals consumer China's economy, with Glencore leading the mining sector lower after poorly-received results.

Miner and commodities trader Glencore was the top FTSE 100 faller, dropping 9.7 percent to a record low after a 29 percent fall in first-half earnings due to a slide in metal and oil prices.

Some questioned whether a decrease in the firm's debt and cuts in capital expenditure went far enough.

"I think that the cutback on the capex wasn't big enough," said Zeg Choudhry, managing director at LONTRAD.

"Obviously (Chinese growth) is not helping, but ...it's the level of debt that the company has which is its biggest problem."

The mining sector dropped 4.7 percent to its lowest level since 2009, hit by weaker metals prices as fears grow that demand from China will take a hit.

Anglo American (LSE: AAL.L - news) , BHP Billiton (NYSE: BBL - news) and Rio Tinto (LSE: RIO.L - news) fell between 4.4 and 3.7 percent.

The blue-chip FTSE 100 index was down 122.84 points, or 1.9 percent, at 6,403.45 points by the close. That was its lowest closing level since Jan. 15, and more than 10 percent below a record high of 7,122.74 points hit in April.

China's stock markets were highly volatile on Wednesday despite government efforts to stabilise them, ending higher after the central bank injected more funds into the financial system for the second day in a row.

Fears over the state of China's economy, the world's second-largest, have eclipsed worries about Greece's debt problems, with the devaluation of the yuan on Aug. 11 adding to concerns.

"General sentiment is fairly skittish at the moment, and the outlook for China certainly hasn't helped," said Richard Hunter, head of equities at Hargreaves Lansdown (LSE: HL.L - news) .

"The FTSE 100 is in negative territory for the year ...and it's quite difficult to see from here what sort of short-term positive impetus the market might take."

Leading the few blue-chip gainers, British insurer Admiral jumped 3.8 percent after posting a forecast-beating 1 percent rise in first-half pre-tax profits.

Pharmaceutical firm Hikma rose 2.5 percent after maintaining guidance for full-year revenue growth.

(Additional reporting by Liisa Tuhkanen; Editing by Andrew Roche)