Credit Ratings

Credit ratings are intended to provide investors with an independent measure of credit quality of an issue of securities. Credit ratings are not recommendations to purchase, hold or sell securities and do not address the market quality or suitability of a specific security for a particular investor. These are assigned by credit rating agencies such as Moody's or Standard & Poor's.

The table below provides a list of the credit ratings assigned to TC PipeLines, LP and the entities in which it has an ownership interest:

TC PipeLines, LP
	Standard & Poor's	Moody's	Fitch
Issuer/Senior Notes Rating	BBB	Baa2	n/a
Trend/Rating Outlook	Stable	Stable	n/a

Gas Transmission Northwest LLC
	Standard & Poor's	Moody's	Fitch
Senior Unsecured	n/a	A3	n/a
Trend/Rating Outlook	n/a	Stable	n/a

Great Lakes Gas Transmission System
	Standard & Poor's	Moody's	Fitch
Issuer Rating	BBB-	n/a	n/a
Trend/Rating Outlook	Stable	n/a	n/a

Iroquois Gas Transmission System
	Standard & Poor's	Moody's	Fitch
Senior Unsecured	BBB+	A3	n/a
Trend/Rating Outlook	Stable	Stable	n/a

North Baja Pipeline LLC
	Standard & Poor's	Moody's	Fitch
Issuer Rating	n/a	n/a	BBB+
Trend/Rating Outlook	n/a	n/a	Stable
Senior Unsecured	n/a	n/a	BBB+
Trend/Rating Outlook	n/a	n/a	Stable

Northern Border Pipeline Company
	Standard & Poor's	Moody's	Fitch
Senior Unsecured	BBB+	n/a	n/a
Trend/Rating Outlook	Stable	n/a	n/a

Portland Natural Gas Transmission System
	Standard & Poor's	Moody's	Fitch
Issuer Rating	n/a	n/a	BBB
Trend/Rating Outlook	n/a	n/a	Stable
Senior Unsecured	n/a	n/a	BBB
Trend/Rating Outlook	n/a	n/a	Stable

Tuscarora Gas Transmission Company
	Standard & Poor's	Moody's	Fitch
Issuer Rating	BBB	n/a	n/a
Trend/Rating Outlook	Stable	n/a	n/a