* Sale of stake expected by bankers for months
* Loss on sale would be "acceptable" for Belgium -investor
* Belgian govt, BNP decline to comment
BRUSSELS/PARIS, Sept 18 (Reuters) - The Belgian governmentmay sell part of its 10.3 percent stake in French bank BNPParibas to bring the country's debt below 100 percentof annual economic output, two Belgian business newspapersreported on Wednesday.
A potential sale of Belgium's stake - worth around 6.3billion-euros ($8.41 billion) - in France's biggest bank, hasbeen mooted as likely by investment bankers for months. It wouldmark another milestone in state exits from holdings in Europeanbanks resulting from bailouts in the 2008 financial crisis.
Belgium took its stake in BNP Paribas following a bailout ofBelgian financial group Fortis, which was taken over by theFrench bank as part of a state-backed rescue.
A sale by Belgium would follow on from the UK government'ssale of a 6 percent stake in Lloyds, which has raisedexpectations the UK might sell its entire stake by mid-2015.
Belgium faces a potential loss on the BNP Paribas stake,according to bankers and investors. The bank is still tradingbelow the purchase price of 68 euros per share despite a reboundin European bank stocks, in which BNP Paribas's shares haverisen almost threefold from 2011 lows.
"At current market levels the loss for the Belgian statewould be acceptable ... It is plausible that they are reallylooking for a way to sell this stake," said Yohan Salleron, fundmanager at Mandarine Gestion, which owns BNP shares.
"A logical outcome would be for BNP to buy back the shares... That would be the best thing for the shareholders."
The Belgian prime minister's office declined to comment andBNP Paribas declined to comment.
BNP Paribas shares were flat at 50.39 euros at 0830 GMT.
A Paris-based trader said a sale of a 5-percent stake seemed"likely".
Belgium has agreed with the European Commission to keep itsdebt below 100 percent of gross domestic product, and would needto find a further 1.8-2.0 billion euros ($2.4-$2.7 billion) fromprivatisations to do that, budget minister Olivier Chastel saidlast week.
Selling around 3 percent of BNP Paribas would be sufficientto raise 2 billion euros to reduce the country's debt, businessdailies De Tijd and L'Echo wrote.