SCOTTISHPOWER has received a boost ahead of its annual general meeting on Friday, after a US judge threw out the $1 billion (£570 million) law suit filed against it by Native Americans.

The Glasgow-based utility has been dogged for over a year by the claims, which relate to the effects of hydroelectric dams on fishing in the Klamath river.

A judge in Oregon dismissed the case as untimely, weakening the power of expected protests from the tribes at the company's AGM. ScottishPower got involved in the case through its ownership of Pacificorp, the US firm it has just agreed to sell at a loss of over £400 million.

A ScottishPower spokesman said he welcomed the decision, although he added that he expected the tribes to appeal the ruling. He said: "Pacificorp believes the decision is appropriate. However, it will continue to work with the Klamath Tribes ... on the complex issues affecting the Klamath Basin."

The row centres on six dams in the north of California. Four tribes - the Klamath, Karuk, Yurok and Hoopa - say the dams have devastated the salmon stock in the area, an important part of their economy, religion and history.

Members of the tribes launched a major publicity stunt at last year's AGM in order to force a commitment from ScottishPower's chief executive, Ian Russell. They will be back again this week, although the sale of Pacificorp will further weaken the push.

The ScottishPower spokesman added: "This issue should really be solved in the US, especially now we are selling Pacificorp."

However, the Native Americans are planning to use the sale to their advantage, accusing the utility of deliberately selling off the division to disrupt talks.