Its revenues narrowed by the indefinite shutdown of its only nuclear plant, Chubu Electric Power Co. has signed a contract to acquire an 80 percent interest in Diamond Power Corp., a small electricity supplier affiliated with Mitsubishi Corp., on Oct. 1 and will consider selling electricity in eastern Japan to expand its earning potential in the future.

Chubu Electric, a regional utility serving the Nagoya region, is reeling from the high cost of fueling its fossil-fuel power stations while the Hamaoka Nuclear Power Station remains offline with no immediate prospect of a restart.

Chubu Electric is anticipating a consolidated net loss for the year through March 2014 for the third year in a row. The utility signed the deal Wednesday to acquire the stake in the power supplier.