The operating rate at utilities was 80.8 percent last month, up from 80.6 percent in September.

The December operating rate at utilities was 81.9 percent, up from 81.3 percent a month earlier.

Production at utilities was up eight-tenths of 1 percent from November.

Executives at several major utilities in the region said they were relieved that the states had decided on a flexible approach.

Officials at most utilities say that some new power is needed to meet growth.

It may take days to restore gas and electricity fully in some areas, officials at utilities said.

But even without the drop at utilities, production expanded slowly last month.

Production at factories, mines and utilities was up 0.2 percent in December.

And an exceptionally warm summer pushed up profits at utilities.

The operating rate at utilities jumped by 1.7 percentage points in August to 82.4 percent.