LAGOS (Reuters) - The Nigerian naira weakened against the U.S dollar on the interbank market and at the central bank's forex auction due to increased corporate demand for the dollar, traders said on Tuesday.
The naira fell after the central bank sold $250 million at 148.41 naira to the dollar at its auction on Monday, short of the $276.82 million demanded. The bank had sold $250 million at 148.35 naira a dollar on Wednesday.

On the interbank market, the naira traded at 150.70 to the dollar compared to 150.55 naira per dollar when it closed on Monday, hit by a sudden surge in demand from a bank trying to meet its customers' needs.

"With a forex auction being held tomorrow (Wednesday) we don't expect the market to be up, but for the fact that dollar liquidity in the system was low due to lack of inflow from oil companies," one dealer said.

Nigerian banks are restricted to funding interbank transactions with dollars bought from oil companies only and are not allowed to transfer forex obtained from the twice-weekly auction to meet interbank need.

Traders said only one oil firm, Addax, sold $2.9 miilion to some banks on Monday and this was not sufficient to help strengthen the naira.

The naira could trade within the present band of 149.89-150.75 naira to the dollar unless there is additional dollar inflow from the state-run energy firm NNPC before the week runs out.