* FTSE 100 down 2.1 pct, six gainers on the index
* Banks, commodity shares the standout losers
* M&S rebounds on market talk of bid interest
By Dominic Lau
LONDON, July 8 (Reuters) - Britain's top share index was down 2.4 percent by midday on Tuesday, tracking sharp losses in the United States and Asia on concerns that financial companies would unveil more writedowns and need to raise more capital.
By 1033 GMT, the FTSE 100 <
> was down 117.5 points at 5,395.8 after gaining 1.9 percent on Monday. The UK benchmark index has fallen 16.5 percent this year."When there is battle on the street and murder on the dancefloor, you've got to start buying. The market is probably going to start a bounce from here," said Manoj Ladwa, a senior trader at TradIndex. "We have been down to these levels before in the last six months and bounced off, although we are not poised for a major rally from here."
European shares were also down sharply.
Banks were among the standout losers on the FTSE 100 following fresh concern the top two U.S. mortgage providers would have to raise even more capital.
Barclays <BARC.L>, Royal Bank of Scotland <RBS.L>, HSBC <HSBA.L>, HBOS <HBOS.L>, Lloyds TSB <LLOY.L>, Alliance & Leicester <ALLL.L> shed between 2.6 and 8.9 percent. Bradford & Bingley <BB.L> lost nearly 20 percent.
Within the financial sector, London Stock Exchange <LSE.L> topped the losers' list, down 8.6 percent as investors pointed to persistent concerns over new equity exchange competitors and greater price competition.
U.S. stocks fell on Monday after Lehman Brothers estimated that a proposed accounting rule would force Fannie Mae <FNM.N> and Freddie Mac <FRE.N> to raise as much as $75 billion between them, while big energy companies fell along with oil prices <CLc1>. In Asia, Japan's Nikkei <
> shed 2.5 percent.Marks & Spencer <MKS.L> recovered earlier losses to be up 1.3 percent as traders cited market talk of possible bid interest in the retailer.
However, the retail sector was weak, with Kingfisher <KGF.L> down 5.5 percent, Sainsbury <SBRY.L> off 3.9 percent and Next <NXT.L> losing 1.3 percent.
Oil shares fell sharply after crude prices <CLc1> lost nearly $4 in the previous day. BP <BP.L> lost 2.7 percent, Royal Dutch Shell <RDSa.L> dropped 2.4 percent and gas producer BG Group <BG.L> slipped 2.6 percent.
Miners also took a battering, with BHP Billiton <BLT.L>, Rio Tinto <RIO.L>, Anglo American <AAL.L>, Xstrata <XTA.L>, Vedanta Resources <VED.L>, Lonmin <LMI.L>, Ferrexpo <FXPO.L> and Eurasian Natural Resources <ENRC.L> losing 2.7 to 4.9 percent.
ON A TIGHTROPE
"If we fall further and close below (the intraday low of 5,338.7 on Jan. 22), then it's going to be a psychological blow to the market because to find a time we have been lower on the FTSE 100 you have to go back to 2005," said Tim Hughes, head of sales trading at IG Index.
"In terms of 'are we in a bear market?' It looks as likely now as ever and I think it will look even more gloomy and bleak in terms of prospectives going forward, if we break the 5,340 mark today."
Investors will keep an eye on U.S. Federal Reserve Chairman Ben Bernanke's comments when he speaks at a conference at 1200 GMT, and U.S. home sales and wholesale inventory data due at 1400 GMT.
GlaxoSmithKline <GSK.L>, Drax <DRX.L> and Petrofac <PFC.L> were the other gainers on the index.
Housebuilder Persimmon <PSN.L>, which is listed on the mid-cap FTSE 250 <
>, fell 3.1 percent after it said the market remained difficult but it did not expect a significant writedown on the value of its land holdings when it reports first-half results in August.Peers Taylor Wimpey <TW.L>, Barratt Developments <BDEV.L>, Bovis Homes <BVS.L>, Bellway <BWY.L> and Redrow <RDW.L> were down 1.1 to 8.3 percent.
Within the real estate sector, Savills <SVS.L> lost 6.4 percent after the property services group said predicting its full-year performance has become "very difficult" as a result of a sharp downturn in property sales in its UK and U.S. markets. (Additional reporting by Michael Taylor; editing by Sue Thomas)