NOTICE DATE: April 21, 2011

NOTICE TYPE: W-A042111-01 Financial/Credit

SHORT DESCRIPTION: Inclusion of estimated uplift costs in TPE calculation related to the ABACUS RESOURCES ENERGY LLC short-pay

INTENDED AUDIENCE: CP, CRRAH and QSE Settlement and Credit Personnel

DAY AFFECTED: April 22, 2011

LONG DESCRIPTION: Due to the short-payment by ABACUS RESOURCES ENERGY LLC for activity in February 2011, ERCOT has short-paid the market by approximately $731,421 to date. The final short-paid amount, net of credits and any remaining collateral held, will be uplifted to the market in September 2011.

At this time, ERCOT has estimated the amount of the uplift based on the short-payment to date and Final settlement data. ERCOT will use the Potential Uplift (PUL) component of the Estimated Aggregate Liability (EAL) calculation to adjust each Counter-Party’s (CP’s) Total Potential Exposure (TPE), starting with the TPE credit calculation generated on April 22, 2011.

The loss share per entity is calculated as defined in Protocol Section 9.19.1, Default Uplift Invoices. This adjustment may be updated from time to time and will remain in place until the short paid amounts are uplifted and billed to the market in September 2011.

ACTION REQUIRED: Settlement and credit personnel should review their EAL Summary Report for the addition of the PUL component.

CONTACT: If you have any questions, please contact Vanessa Spells at [log in to unmask], (512) 225-7014 or Rizaldy Zapanta at [log in to unmask], (512) 225-7015. Additional questions can be directed to your assigned ERCOT Account Manager, [log in to unmask] or (512) 248-3900.

If you are receiving email from an ERCOT distribution list that you no longer wish to receive, please follow this link in order to unsubscribe from this list: http://lists.ercot.com.