FTSE opens sharply down as miners fall; A

LONDON, May 22 (Reuters) Britain's top share index tumbled at the opening on Monday, extending a two-week rout and tracking losses in Asia, as lower metals prices knocked miners such as Kazakhmys , but bid speculation boosted bank Alliance&Leicester .

By 0726 GMT, the FTSE 100 share index was 52.2 points, or 0.9 percent, lower at 5,605.2 points, having earlier dipped as low as 5,576.4 points -- its lowest since December 2005 ''It's following on from Asia,'' said one London-based dealer, pointing out weakness in mining stocks due to lower metals prices and sustained global inflation worries.

''Commodity prices are lower -- you would think that would ease inflation fears but the market is just following its tail at the moment.'' The FTSE 100 is about 530 points, or 8.7 percent, below a five-year high reached in April which had been driven by soaring commodity prices, rampant bid activity and solid earnings.

The index has lost about 480 points in the last two weeks and finished last week 254.7 points, or 4.3 percent, lower -- its biggest weekly points drop since July 2002 and largest weekly percentage fall since March 2003.

Miners contributed about 20 points to FTSE weakness on Monday, as lower metals prices -- such as losses in gold, copper and zinc -- weighed on the sector.

Kazakhmys led the losers, down 9 percent. Antofagasta fell 7.1 percent, Xstrata dropped 5.6 percent and Anglo American lost 3.6 percent.

Demand for raw materials has surged in recent years thanks to booming growth in countries such as China and India and robust economic performance in the United States -- boosting the earnings and share prices of mining companies.

But increasing concern over rising interest rates and inflation has shaken confidence in the sustainability of such growth and investors have rushed to book profits made in the mining sector as equity markets have fallen.

Oil and gas producers such as BG Group also fell after crude oil prices slipped more than 1 percent.

Bucking the broad losing trend, lender Alliance&Leicester leapt 10 percent after French peer Credit Agricole said it was assessing a possible bid for the UK bank but added it had yet to make a proposal.

REUTERS PV RK1325