The following companies are the major competitors of WGL Holdings, Inc.
- Nicor Inc.
- Allegheny Energy, Inc.
- National Fuel Gas Company
- KeySpan Corporation
- Pepco Holdings
- Atmos Energy Corporation
- AmeriGas Partners, L.P.
- AGL Resources Inc.
- Piedmont Natural Gas Company, Inc.
- UniSource Energy Corporation
- New Jersey Resources Corporation
- Northwest Natural Gas Company
- EnergySouth, Inc
