Mirant agrees to supply power for customer demand in New Hampshire

ATLANTA, Ga., March 17, 2003 — Mirant announced that it has agreed to provide electricity to Unitil Energy Systems, Inc. (Unitil) for Transition and Default Service to its New Hampshire customers. This agreement provides Mirant with long-term contracts in the Northeast and was approved by the New Hampshire Public Utility Commission (NHPUC) on March 14.

“Mirant continues to expand its presence by adding customers in the Northeast, a key region for our company,” said Tim Berrigan, vice president, marketing, Mirant. “Our agreement with Unitil demonstrates Mirant’s commitment to being a long-term participant in New England’s electricity market. Long-term contracts like these are a critical component to any well-functioning competitive market.”

Mirant will provide approximately 260 megawatts of wholesale electricity to Unitil from its portfolio of assets in the region. Unitil will resell the electricity to its residential, commercial and industrial customers in New Hampshire.

This agreement with Unitil is being conducted pursuant to orders of the NHPUC to implement retail electric competition in New Hampshire effective May 1, 2003.

Under this agreement, Mirant will also assume eight contracts for electric generation that utilize diverse fuel sources.

Unitil is a public utility holding company with subsidiaries providing electric service in New Hampshire, electric and gas service in Massachusetts and energy services throughout the Northeast.

Specific terms of Mirant’s contract with Unitil were not disclosed.

Visit Mirant at www.mirant.com.