HOUSTON, March 8 (Reuters) - Nigeria's Seplat Energy is on track to buy Exxon Mobil's offshore shallow water business in the country for $1.28 bln, Seplat's chairman told Reuters on the sidelines of CERAweek energy conference by S&P Global.

The comments come amid media reports that Nigerian National Petroleum Company Limited (NNPC) was looking to block the deal.

"We believe the government will grant the approval based on the merit of the transaction," Seplat's chairman, Ambrosie Bryant Chukwueloka Orjiako, said. (Reporting by Arathy Somasekhar in Houston; Editing by Leslie Adler)