Fitch affirmed the firm’s foreign and local currency ratings for US$300M in unsecured notes due in nine years, and said the rating outlook is stable.

The stable outlook arises from AES Panama’s varied, low-cost asset base of four hydro plants, which have competitive dispatch positions and the company’s power purchase agreements. The plants are of varied type (reservoir and run-of-river) and are sited in different hydrological environments.

AES Panama’s four plants have combined capacity of 482MW, and are: the 260MW Bayano plant, which operates during peak load hours ahead of more expensive thermal units; the 120MW Esti plant, which also has a good dispatch position as the limited size of its reservoir enables it to be taken as similar to a run-of-river facility; and the 54MW Los Valles and 48MW La Estrella plants, which are run-of-river facilities that are the first to be dispatched in the system.

The company has power purchase agreements (PPAs) of various periods with the country’s three distribution firms, two of which – Edemet and Edechi – it recently signed a new contract with for 50MW at US$81.05/MWh.

Fitch said the new PPA contract was expected to help support development of a new hydro project – the Changuinola plant. The agency said the project would enable the firm capacity that AES Panama could contract to be increased by a net of 50MW. The Chinguinola scheme is expected to be commissioned in 2010.