NEW YORK – A Washington, D.C., regulator approved Exelon’s nearly $7 billion takeover of rival utility Pepco, but the deal will only go through if Exelon agrees to the regulator’s terms.

The District of Columbia Public Service Commission said Wednesday that Exelon has 30 days to agree to the way it wants more than $70 million in payments to be used for customer discounts and energy conservation.