The chief financial officers of New York City and the state of California have asked Rio Tinto plc to sell its shares of the company behind the proposed Pebble Mine project in southwest Alaska.

New York City Comptroller John Liu and California State Controller John Chiang said they oversee pension funds that are substantial, long-term shareowners in London-based Rio Tinto. The company owns a 19 percent share of Northern Dynasty Minerals Ltd., which recently assumed full ownership of the mine project.

The financial officers, in a letter dated Thursday to Rio Tinto CEO Sam Walsh, said they found the company’s response to their concerns about the project’s possible legal and regulatory risks perfunctory. They also said there were risks to Rio Tinto’s reputation for being associated with Pebble, a massive gold-and-copper prospect near the headwaters of a world-premier salmon fishery in Alaska’s Bristol Bay region.

They said they believed those risks outweighed the market value of Rio Tinto’s shares in Northern Dynasty.

Read the full story at the Juneau Empire>>