A petrol station attendant counts Nigerian's currency, the naira, depicting Nigeria's first president, in Abuja, Nigeria.Photographer: Suzanne Plunkett/Bloomberg News

Lagos - Nigeria's economy slowed in the final quarter of 2015 from the previous three months and annual growth remained far weaker than the previous year after the plunge in crude prices slashed government revenues and weakened the currency.

The Nigerian Bureau of Statistics (NBS) said year-on-year growth during the three months to December slowed to 2.11 percent from 2.84 percent in the third quarter, slower than the 5.94 percent recorded in the fourth quarter of 2014.

Economic challenges have been mounting as cheap oil slashes vital revenues from crude sales, forcing the central bank to introduce currency curbs to conserve foreign exchange reserves which have fallen to a more than 11-year low.

President Muhammadu Buhari has rejected calls by the International Monetary Fund to lift foreign exchange curbs and allow a more flexible rate for the naira currency, backing the central bank's actions.

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The tight dollar restrictions have forced domestic lenders to delay hard currency loan and trade repayments to foreign banks and increased the risk of default, bankers say.

Foreign funds fled Nigerian assets as the oil price decline worsened, further weakening the naira and helping fuel inflation which is currently outside the central bank's target range at 9.6 percent.

The NBS said oil production was 2.16 million barrels per day in the fourth quarter, slightly lower than 2.17 million barrels recorded in July-September but more than the 2.05 million bpd pumped in the second quarter.