FTSE drops to one-week low as commodity shares, Vodafone slump

* Blue-chip FTSE 100 index falls 0.9 percent

* Oil price continues slide, China data hits miners

* Vodafone knocked by takeover speculation (Adds detail, quote)

By Alistair Smout

LONDON, Dec 1 (Reuters) - Britain's top stock index dropped to its lowest in more than a week on Monday as commodity shares slumped and Vodafone fell on speculation it is considering possible acquisitions.

Weak Chinese economic data compounded concern over commodity stocks. An official reading showed growth in China's factories slowed more than expected in November. A private-sector survey showed momentum stalled.

The FTSE 350 mining sector fell 2 percent to its lowest since July 2013. Oil and gas stocks were down 1.3 percent after touching a 3 1/2-year low.

Brent oil fell more than $2 a barrel to a five-year low, extending last week's losses after OPEC decided not to cut production. Gold slid 2 percent as Swiss voters rejected forcing the central bank to increase its gold reserves. Copper tumbled to a 4 1/2-year low.

"Mining and energy stocks have given up considerable ground on the back of China manufacturing data, confirming a slowing of economic growth and adding to existing commodity weakness," Mike van Dulken, head of research at Accendo Markets, said.

Shares (Frankfurt: DI6.F - news) in BG Group (LSE: BG.L - news) fell 2.3 and Weir Group lost 2.6 percent. Tullow Oil (LSE: TLW.L - news) dropped 5.8 percent after Citigroup (NYSE: C - news) and JPMorgan cut their target prices for the shares. Overall, oil, gas and mining stocks trimmed over 20 points off the index.

The FTSE 100 fell 0.8 percent to 6,667.59 points by 1215 GMT after falling as low as 6,641.46, the lowest since Nov. 20. It is down just over 1 percent this year.

Vodafone, the second biggest decliner, fell 4.6 percent and trimmed 10.8 points off the index, more than any other stock.

Traders said the fall was caused by speculation Vodafone was reviewing potential acquisitions. Reuters reported on Friday it was considering a deal for Europe's leading cable operator, Liberty Global (NasdaqGS: LBTYA - news) .

"While we see clear strategic logic in a LBTY deal, its size and timing may be negative for VOD investor sentiment," analysts at UBS (NYSEArca: FBGX - news) said in a note.

Aberdeen Asset Management (Other OTC: ABDNF - news) rose 4 percent after saying underlying pre-tax profit rose 2 percent to 490 million pounds ($766 million). However, it reported 20 billion pounds ($31.3 billion) of net outflows, citing weakness in emerging markets. (Editing by Larry King)