* Barclays cuts stake in African unit to 50.1 pct
* Placement at a 6.5 percent discount
* South African state pension fund biggest buyer of theshares
* Bob Diamond's Atlas among investors interested (Adds details, analyst comment)
By Sinead Cruise and Tiisetso Motsoeneng
LONDON/JOHANNESBURG, May 5 (Reuters) - Barclays raised 603 million pounds ($876 million) on Thursday by sellinga 12.2 percent stake in Barclays Africa Group, acrucial first step in a plan to curb risk and refocus on coremarkets in Britain and United States.
Barclays' retreat from Africa may include selling theremaining 50.1 percent stake to a strategic investor, withformer Barclays' boss Bob Diamond already lining up financing.
That would end more than a century of involvement by theBritish lender in the continent, whose growth prospects weredealt a blow in 2014 when the price of oil and other commodities- export mainstays of many African economies - collapsed.
The sale is also part of the bank's plan to simplify itsstructure, shore up its balance sheet and generate highershareholder returns. Barclays held a 62 percent holding in thecompany before the placement.
The sale of 103 million shares, priced at 126 rand each - adiscount of 6.5 percent to Thursday's closing price - wasoversubscribed multiple times and attracted "very high qualitydemand" from domestic and international investors, a sourcefamiliar with the matter said.
Shares in Barclays Africa dropped as much as 4 percentbefore recouping some of the losses to close 2.3 percent lowerat 131.60 rand.
"It does seem like a discount but it is also a large chunkof stock that is listed in an environment that has certainlybeen very volatile," said Lentus Asset Management's ChiefInvestment Officer Nic Norman-Smith. "It's kind of 'just get meout'"
Barclays did not give details of the investors who took partin the placing but a source familiar with the matter said thePublic Investment Corporation (PIC) took up 10.3 million shares,or a tenth of the $876 million, the most by a single investor.
PIC, Africa's largest fund manager with more than $122billion of South African government employee pension assets inits custody, will now own almost 7 percent of the BarclaysAfrica. It was already the second biggest shareholder inBarclays Africa before the transaction.
The PIC has an option to increase its holding beyond 7percent without seeking further regulatory approval, the sourcesaid. Investors who took part in the placement were pre-approvedby the South African Reserve Bank, the source said.
The asset management arm of Anglo-South African insurer OldMutual, a top 10 investor in Barclays Africa, was also amonginvestors that took part in the private placement, its spokesmansaid.
DIAMOND
The window may still be open for Atlas Mara, anAfrica-focused financial services company, to a launch a bid forBarclays' entire remaining stake in Barclays Africa, SouthAfrica's No.3 lender with a market value of 114 billion rand($7.62 billion).
The stake is worth around $4.4 billion based on the placingprice.
Valued at $330 million, Atlas Mara - a company set up byformer Barclays Chief Executive Diamond - has teamed up withinvestors that a source has said included buyout firm Carlyle tolaunch the bid.
However, any deal involving a private equity player willface regulatory opposition from South Africa's central bank,whose deputy governor Kuben Naidoo said this week the bank wouldnot be comfortable with a private equity fund in any of thelocal banks.
Diamond has not elaborated on what form the financing he hasput together would take.
Barclays Africa said the results of the private placementshowed there was strong demand for its stock and also gave itsparent options to sell in capital markets or to a strategicinvestor.
The deal is expected to result in a pro forma increase ofabout 10 basis points in Barclays' common equity tier 1 ratio, akey measure of the bank's financial strength. Shares in thebank, which have fallen 25 percent so far this year, closed 0.9percent lower at 160.95 pence. ($1 = 14.9599 rand)($1 = 0.6902 pounds)
(Additional reporting by TJ Strydom in Johannesburg; Editing byAdrian Croft)