UK FTSE posts biggest one-day fall in over a week

* FTSE 100 closes down 3 pct, its biggest one-day fall in

over a week

* Disappointing China data rattles global markets

* Only one FTSE 100 components closes in positive territory

* Mining stocks BHP Billiton (NYSE: BBL - news) , Anglo American (LSE: AAL.L - news) down over 6 pct

* Engineering firm Meggitt (Other OTC: MEGGF - news) is top gainer

(Refiles to remove UPDATE tag in headline)

By Kit Rees and Lionel Laurent

LONDON, Sept 1 (Reuters) - The UK FTSE 100 slumped 3 percent

on Tuesday, its worst one-day fall in over a week, with miners

hit hardest after a slump in the manufacturing sector in China -

the world's biggest commodity consumer.

All but one FTSE 100 stock closed in negative

territory on Tuesday, London's first trading day of the week

after a public holiday on Monday.

Policymakers worldwide have turned more interventionist with

a surge in market volatility to levels not seen since the 2008

financial crisis. China's central bank has already repeatedly

intervened to stabilise the yuan since its Aug. 11 devaluation

sent shockwaves through global markets.

"We are sellers across the board," said Mark Ward, head of

execution trading at London-based Sanlam Securities. "People are

getting back from holidays and trying to make sense of what is

going on.

"The China headlines are not helping but I would say it's

probably more down to sentiment than a huge shift in the actual

economic outlook."

The FTSE 100 lagged the pan-European FTSEurofirst 300

, down 2.9 percent.

"As it stands we've pretty much wiped off any of the gains

we saw last Friday ... it does seem like this could be another

return to the lows we saw last week, particularly if we don't

see any effects from the Chinese interventions any time soon,"

said Brenda Kelly, head analyst at London Capital Group.

China's official Purchasing Managers' Index (PMI) fell to

49.7 in August from the previous month's reading of 50.0, the

weakest showing in three years.

That was followed by releases of weak PMI data for both

Britain and the euro zone showing manufacturing growth had eased

last month.

The index's top gainer was engineering components firm

Meggitt, rising 2.4 percent, with a trader citing a

pick-up in auto sales and a government pledge to spend more than

500 million pounds refurbishing a nuclear submarine base in

Scotland. [ID:nL5N1172TB}

Miners Glencore, Anglo American and BHP

Billiton were down more than 6 percent, leading the

fallers as metals prices fell on China demand fears.

In the mid caps, China worries also hit shares of hedge-fund

manager Man Group (LSE: EMG.L - news) , down 6.8 percent after the boss of

its China unit was reportedly taken into custody as part of a

probe into the causes of recent market volatility.

(Reporting by Lionel Laurent; Editing by John Stonestreet and

Raissa Kasolowsky)