* Oils, miners, rally with commodity prices
* Retailers buoyed by Debenhams results
* Banks weak after Morgan Stanley loss
* Pharmas retreat led by GlaxoSmithKline
By Jon Hopkins
LONDON, April 23 (Reuters) - Britain's leading shares were up 1 percent at midday on Thursday, with gains from commodity issues and by retailers, offsetting weakness in bank and drug stocks.
By 1231 GMT, the FTSE 100 index was 41.50 points higher at 4,072.16, after closing up 43.2 points, or 1.1 percent at 4,030.66 on Wednesday.
"The London market is holding quite nicely through the morning session ... given the surreal growth assumptions that Alastair Darling et al delivered on Wednesday," said Manus Cranny, senior market commentator for MF Global Spreads.
"The market seems to have shrugged of the sharp sell off into the U.S. close on Wednesday. There is a suspicion that this move has all the hallmarks of a mini bear squeeze."
Oil stocks added the most points to the index, pushing higher as crude prices <CLc1> rebounded back above the $49.50 level. BP <BP.L>, Royal Dutch Shell <RDSa.L>, BG Group <BG.L>, Tullow Oil <TLW.L>, and Cairn Energy <CNE.L> added 1.4 to 5.5 percent.
Miners saw also gained as metal prices stabilised after recent falls, with copper reversing earlier losses. Rio Tinto <RIO.L>, Xstrata <XTA.L>, BHP Billiton <BLT.L>, Kazakhmys <KAZ.L>, and Antofagasta <ANTO.L> gained between 0.8 and 4.0 percent.
Lonmin <LMI.L> stood out, up 8.3 percent after the platinum miner issued a reassuring production update. [
]Lonmin said platinum sales rose 30 percent in the second quarter and reaffirmed its 2009 guidance, prompting Cazenove to raise its rating to "in-line" from "underperform".
Retailers built on Wednesday's advance, following solid results from mid-cap department-store group Debenhams <DEBS.L>.
Debenhams saw its first-half pretax profit and sales beat market forecasts, and said trading had improved in the first weeks of its second half. [
]The retailer topped the FTSE 250 <
> leaderboard, up 23.6 percent, while blue-chips Next <NXT.L>, Marks & Spencer <MKS.L> and Home Retail Group <HOME> gained 4.0 to 6.4 percent.Testing equipment group Intertek <ITRK.L> was the top blue chip gainer, up 10.7 percent as bid talk returned for the group, with Switzerland's SGS <SGS.VX> seen as the possible predator.
BANKS BEAT RETREAT
Banks saw some of Wednesday's resillience fade after falls overnight by U.S. peers as results from Morgan Stanley <MS.N> undermined the recent more upbeat trend in the depressed sector.
HSBC <HSBA.L>, Lloyds Banking Group <LLOY.L>, lost 0.6 and 0.1 percent respectively.
Barclays <BARC.L> gained 0.6 after it held its annual general meeting. The bank said its first quarter performance was well ahead of the same period last year, and that it intends to resume paying dividends in the second half of 2009. [
]Among the other financial companies, fund manager Schroders <SDR.L> shed 2.6 percent after reporting a 54 percent drop in first-quarter pretax profit and saying the high level of market volatility continued to affect investor demand. [
]Falls by drug heavyweight GlaxoSmithKline <GSK.L> was the main drag on blue chips, with losing 2 percent on further reflection of Wednesday's disappointing first quarter.
Shire <SHP.L> bucked the weak sector trend, rising 5.2 percent, as vague bid speculation returned for the group.
"After yesterday's budget, the market is in a bit of a no-man's land at the moment, just toying with the 4,000 level as investors wait for something to more to pull the market one way or another," said Tim Hughes, head of trading at IG Index. (Editing by Karen Foster)