Nigeria's central bank has sold $15.8 million at 1,101 naira per dollar, firmer than the official market rate, to the country's bureau de change operators to meet demand for individual foreign exchange needs, it said on Monday.

The currency of Africa's biggest economy traded at 1,245 naira per dollar at 0936 GMT on the official market.

The central bank said in a notice that it had sold $10,000 each to 1,588 bureau de change operators to meet eligible retail market demand and told operators to sell in turn to end users at a spread of not more than 1.5% above the purchase price.

The central bank is trying to boost liquidity on its currency market, which has suffered chronic dollar shortages.

It delivered two large rate hikes in February and March and increased the yields on short term treasury bills to draw foreign investors.

The naira has gained sharply against the dollar on both the official and parallel markets after suffering its second devaluation in less than a year in January as the central bank raised rates and lifted restrictions on foreign participation at its fixed-income auctions.

Central bank governor Olayemi Cardoso has said he will work to strengthen the currency and bring down inflation.

Cardoso also said that the naira, which has been in freefall, will adjust once rules for market participants are made clear. (Reporting by Chijioke Ohuocha; Editing by Alison Williams, Jan Harvey, Philippa Fletcher)