LAGOS, May 5 (Reuters) - Nigeria's central bank raised more money from a sale of treasury bills than originally planned at an auction this week after it priced its one-year debt to yield more than inflation, in a bid to support the currency.
The bank raised 230.60 billion naira ($733 million) at an auction on Wednesday, 80.60 billion naira more than it originally planned to sell, data showed on Friday.
Treasury bill sales support the currency by draining some of the naira in the market, thereby making the naira slightly stronger against the dollar.
The central bank has been intervening since February to prop up the naira after introducing a complex, multi-tiered exchange rate system.
It has sold more than $4 billion on the spot and forward currency markets and has been attracting investors in recent months to its one-year debt with high yields.
The bank offered the one-year debt with a yield of 18.81 percent, higher than the March inflation rate of 17.26 percent, to raise 178.60 billion naira. The note was sold at 18.98 percent previously.
It sold six-month bills at 17.26 and a three-month debt at 13.6 percent to fetch a total of 52.57 billion naira.
The central bank issues treasury bills twice a month to help the government fund its budget deficit and to help it control inflation. ($1 = 314.5000 naira) (Reporting by Oludare Mayowa; Editing by Chijioke Ohuocha and Hugh Lawson)