* Oils, miners fall with commodity prices
* Banking sector pulled up by HSBC
* Vodafone gains on Goldman Sachs upgrade
By Jon Hopkins
LONDON, April 1 (Reuters) - Britain's top share index was 0.6 percent lower by midday on Wednesday retreating after sharp gains in the previous session, weighed on by weakness in commodity stocks but leavened by rises in HSBC <HSBA.L> and Vodafone <VOD.L>.
By 1102 GMT the FTSE 100 index <
> was 23.75 points lower at 3,902.39, after jumping 163.23 points, or 4.3 percent, on Tuesday."Trading is choppy, with markets likely to remain volatile ahead of the G20 summit," said Nick Serff, market strategist at City Index.
"Trading is ... focused on macroeconomic announcements with little in the way of corporate news. ADP Employment figures from the U.S. are likely to be the biggest market mover and should give a guide to this Friday's U.S. non-farm payrolls," he said.
Wall Street ended higher overnight but U.S. stock futures <SPc1> pointed to a big retreat on Wednesday after General Motors <GM.N> warned late on Tuesday there was a rising chance it could file for bankruptcy in June.
Energy stocks were under pressure as crude fell almost 3 percent towards $48 per barrel, with BG Group <BG.L> and BP <BP.L> losing 0.8 and 2.9 percent respectively.
Royal Dutch Shell <RDSa.L> was the biggest FTSE 100 faller, down 4.3 percent. Morgan Stanley was placing 10.9 million shares in the Anglo-Dutch firm, traders said.
Mining heavyweights also retreated with metal prices and after some negative comments from Morgan Stanley.
The broker cut ratings for Antofagasta <ANTO.L> and BHP Billiton <BLT.L>, but raised target prices for a number of other players, in a sector review.
Antofagasta shed 2.4 percent, with BHP down 3.0 percent, while Lonmin <LMI.L>, Vedanta Resources <VED.L>, and Anglo American <AAL.L> lost between 1.0 and 3.6 percent.
Eurasian Natural Resources <ENRC.L> fell 2.3 percent as investors lost the right to its dividend, with Alliance Trust <ATST.L> and Smiths Group <SMIN.L> also trading ex-dividend.
Drug stocks were also weak, with Shire <SHP.L> losing 3.5 percent on profit-taking after strong gains Tuesday following a co-promotion deal with GlaxoSmithKline <GSK.L>, down 1.8 percent
HSBC RESCUES BANKS
The banking sector was the best performer at midday, mainly because of a 4.8 percent jump by HSBC with the stock boosted by technical factors associated with its cash call, with Wednesday the last day of trading for nil-paid rights shares.
Barclays <BARC.L> edged up after missing out on sector gains on Tuesday, up 1.4 percent.
But Lloyds Banking Group <LLOY.L> lost 2.1 percent.
A clawback in British government-held shares in Lloyds Banking Group by private investors, due to a share price differential, could cut the amount of taxpayers' cash the bank will need, Treasury minister Paul Myners said. [
]Vodafone Group <VOD.L> put on 3 percent as Goldman Sachs hiked its rating to "buy" from "neutral" and added the stock to its "conviction buy list" in a review of the telecoms sector.
But BT Group <BT.L> fell back 2.7 percent after Goldman Sachs cut its rating to "sell" from "neutral".
Tour operator Thomas Cook Group <TCG.L> shed 2.5 percent as Morgan Stanley downgraded its rating to "equal-weight" and advised a switch to TUI Travel <TT.L>, up 1.7 percent, which it upgraded to "overweight".
Retailers found support again following Tuesday's reassuring trading news from Marks & Spencer <MKS.L>, up 3.3 percent.
Argos-owner Home Retail Group <HOME.L> was the top blue chip riser, up 6.3 percent, while Kingfisher <KGF.L> and Next <NXT.L> gained 4.1 percent and 2.8 percent respectively. (Editing by Greg Mahlich)