Portland Natural Gas Transmission System

Second Revised Volume No. 1

Effective Date: 09/01/2006, Docket: RP06-449-000, Status: Effective

Original Sheet No. 339 Original Sheet No. 339 : Effective

GENERAL TERMS AND CONDITIONS (Continued)

8.10 Imbalance Trading and Netting

Imbalance Trading is available for any daily imbalance that would

otherwise be resolved pursuant to Section 8.3(b) above. Transporter will allow

Shippers to trade daily imbalances if the two daily imbalances offset each

other in such a way that the net daily imbalance after the completion of the

trade for each Shipper would be reduced to a quantity closer to zero. A

Shipper may trade any daily imbalance with another Shipper, provided that the

trade does not violate any notices issued by Transporter relating to operation

of Transporter's system. A Shipper may net imbalances between its service

agreements.

Imbalance trading may be done at any time during the gas flow month, and

until the seventeenth Business Day after the end of the month. To facilitate

the trading process, Transporter will, upon receipt of Shipper's

authorization, post the Shipper's daily imbalance quantity on Transporter's

Interactive Internet Website. Authorizations to post imbalances that are

received by Transporter by 11:45 A.M. will be effective by 8 A.M. the next

business day (central clock time). An authorization to post imbalances will

remain in effect until cancelled by the Shipper giving the authorization.

Daily imbalances previously authorized for posting will be posted as they

become available, but no later than the ninth business day of the month;

however, Transporter will not be required to post zero imbalances. The

information posted will also identify the contract, the area where the

imbalance arose and the gas day applicable to the posted daily imbalance

quantity. Transporter will provide to all customers the ability to view, and

upon request, download posted imbalance information.

Transporter shall enable the imbalance trading process by (i) receiving

the request for imbalance trade, (ii) receiving the imbalance trade

confirmation, (iii) sending the imbalance trade notification to all affected

parties, and (iv) reflecting the trade prior to or on the next monthly Shipper

Imbalance. When trading imbalances, the quantity to be traded must be

specified. After receipt of an imbalance trade confirmation, Transporter will

send the imbalance trade notification to the initiating trader and the

confirming trader no later than noon (central clock time) on the next business

day. Imbalance trades can only be withdrawn by the initiating trader and only

prior to the confirming trader's confirmation of the trade. Imbalance trades

are considered final when confirmed by the confirming trader. Transporter

shall update the Shipper's daily imbalance data to reflect any final trades of

imbalance quantities no later than 9 a.m. CT on the next business day after

the trade is finalized.