* FTSE 100 rises 0.7 pct by midday
* Banks weigh, but RBS rises after Merrill initiates "buy"
* Oils turn positive as crude trims losses
* Tesco gains after trading update
By Dominic Lau
LONDON, Dec 2 (Reuters) - Britain's top share index had edged up by midday on Tuesday, as grocer Tesco <TSCO.L> soared after a trading update and oil stocks recovered from earlier losses, offsetting weakness in the banks.
By 1116 GMT the FTSE 100 <
> was up 29.59 points, or 0.7 percent at 4,095.08, after falling as much as 2.3 percent earlier in the session. The UK benchmark slid 5.2 percent on Monday and is down more than 36 percent for the year on fears of a deep global recession.Tesco, Britain's biggest retailer, said its new budget range was luring an extra 300,000 shoppers a week, boosting its shares on hopes it may be better placed to cope with a recession than its rivals. Tesco shares were up 7.9 percent.
Within the food retailing sector, Sainsbury <SBRY.L> sagged 2.6 percent but Morrison Supermarkets <MRW.L> gained 2.5 percent.
Oil shares recovered earlier weakness to trade higher as crude prices <CLc1> trimmed losses. BP <BP.L> advanced 2.5 percent and Royal Dutch Shell <RDSa.L> strengthened 2.8 percent.
Oil services firm Petrofac <PFC.L> rose 10.9 percent.
"The volumes are still fairly low. There is a rumour doing the round that (U.S. Treasury Secretary Henry) Paulson has secured another $150 billion for the banks, but nothing concrete there," said Manoj Ladwa, senior trader at ETX.
Paulson said on Monday that more programmes were being developed to stimulate lending but the severe financial crisis was stubbornly persisting.
Ladwa also said the market was expecting the U.S. Federal Reserve to make a hefty interest rate cut from the current 1 percent. The Fed holds a two-day rate-setting meeting on Dec 15 and 16.
Banks were the top-weighted losers on the FTSE 100 amid the darkening global economic outlook. Barclays <BARC.L>, HSBC <HSBA.L>, Lloyds TSB <LLOY.L>, HBOS <HBOS.L> and Standard Chartered <STAN.L> shed between 0.6 and 4.1 percent.
Meanwhile the Wall Street Journal said Goldman Sachs <GS.N> is likely to report a net loss of as much as $2 billion for the fourth quarter.
Royal Bank of Scotland <RBS.L>, however, advanced 5.1 percent after Merrill Lynch restarted coverage on it with a "buy" rating and says it should have time to implement a strategic overhaul.
SHRINKING CONSTRUCTION SECTOR
Britain's construction sector shrank last month at its fastest pace since records began a decade ago as falling property prices and a shortage of credit took an increasingly heavy toll, a survey showed. [
]Investors will eye interest rate decisions this week from both the Bank of England and the European Central Bank. The two central banks are expected to serve up further monetary policy easing on Thursday.
Later in the day, U.S. ADP National Employment data for November will give some indication for the closely-watched non-farm payrolls employment data due out on Friday.
The U.S. economy has been in recession for a year, the nation's business cycle arbiter, the National Bureau of Economic Research declared on Monday.
Overnight, Australia slashed interest rates by a full percentage point and Japan's central bank said it would accept a wider range of corporate debt as eligible collateral to ease Japanese companies' quickly shrinking access to funding as the end of the year approaches.
Miners also pared losses. Vedanta Resources <VED.L> surged 10.9 percent after the India-focused miner said it would spend $250 million on buying back up to 10 percent of its shares.
Thomas Cook <TCG.L> rose 5.4 percent after Europe's second-biggest travel firm reported a sharp rise in full-year profits and raised its final dividend. Rival TUI Travel <TT.L> added 1.1 percent. (Editing by Greg Mahlich)