"The response matches our expectations and indicates the strength of interest in the WA electricity market," said Western Power power procurement manager, Trevor Harvey.

"The expressions of interest will be studied over the next weeks and those that qualify will be invited to submit indicative bids. A short list will later be asked to submit firm bids."

Harvey said the new power station should be ready by 2007 or 2008.

Western Power has not disclosed the identity of 11 parties who lodged expressions of interests for the power station. However, the two bids known to the public both involve Japanese partners.

Japanese trading house Mitsui & Co has teamed up with Ric Stowe's Griffin Energy group while Wesfarmers has joined forces with Japanese electricity wholesaler, J-Power, to also make a bid.