NEW YORK (AP) - 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.

NEW YORK (AP) 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.

Exelon, based in Chicago, said it is reviewing the order.

The District of Columbia Public Service Commission is the last regulator Exelon needed approval from to cinch the deal. The Federal Energy Regulatory Commission and commissions in four states have already approved it.

Shares of Washington-based Pepco Holdings Inc. soared 28 percent Wednesday afternoon. Exelon Corp. shares slipped less than 1 percent.