INFLATION in Nigeria rose sharply in the second half of 1998, hitting an estimated annual rate of 15% in December, according to a government report published on Wednesday. “Inflation rose from a low level of 6% in the 12-month period ending March 1998 to an estimated 15% in December 1998,” says the report prepared by the government for the International Monetary Fund. The report said the government will seek to restrict the growth in prices and pursue tight monetary policies to bring the rate back down. Local newspaper reports also said the government told the IMF that Nigeria Airways, the National Fertiliser Company of Nigeria and the Kaduna (oil) Refinery will be privatised before president-elect Olusegun Obasanjo assumes power on May 29.