The installation of Pepco smart meters that the company hopes will lead to approval of a rate increase for customers is behind schedule.

About 429,000 Maryland Pepco customers — roughly 78 percent — have the devices installed, Pepco spokesman Marcus Beal said. Smart meter installation began in July and was expected to wrap up before the beginning of the new year. The remaining 121,000 customers should expect their installations to be completed by the end of January, Beal said.