ST. PAUL, Minn. — Minnesota's state pension fund approved a shareholder resolution on Wednesday opposing efforts by Pfizer Inc. to cut off supplies to Canadian pharmacies that sell to Americans.

Gov. Tim Pawlenty described the resolution as a new front in a battle against pharmaceutical companies that charge high prices to Americans and then thwart efforts by states to shop around.

Pawlenty said he planned to send letters to other governors asking them to consider having their pension funds join the effort.

Three of the four members of the State Board of Investment approved the measure; Secretary of State Mary Kiffmeyer opposed it, saying she's concerned it might depress payments to retirees, which are based on the fund's overall performance.

She said the move could depress the value of the state's own shares of Pfizer's stock and in turn affect state payments to retirees, which are based on the pension fund's overall performance.

The vote directed investment board staff to draft a resolution that could be placed on Pfizer's proxy statement to be sent to investors before its annual meeting in spring 2005. Directors of other state pension funds will be asked to co-sponsor the resolution, said Howard Bicker, executive director of the board. He said it will likely be nonbinding.

Last month, Minnesota launched a website that helps residents import medications from Canada.

"We're in a dogfight with these companies and when you're in a dogfight you need some tools and this is one tool," he said.

Minnesota's State Board of Investment owns about 12.8 million shares of Pfizer stock, worth about $476 million US. The company's total value is about $280 billion.

Pfizer started shutting off shipments to two Canadian wholesalers last week. The week before, it stopped shipping product to several Canadian Internet pharmacies.

The resolution demands that Pfizer cease efforts to limit the availability of its products, including cholesterol-lowering drug Lipitor, the world's best-selling medicine, to Canadian wholesalers or pharmacies that sell to non-Canadians.

Late last year, Minnesota Attorney General Mike Hatch launched an investigation into whether GlaxoSmithKline and other drug companies are in an illegal conspiracy as they limit drug sales to Canadian pharmacies.

Hatch and State Auditor Pat Anderson both voted for the resolution after Hatch amended it to broaden its language to include large pharmaceutical companies other than Pfizer.

By law, the investment board's top duty is to maximize returns but Pawlenty said that's what he intends with the effort. The resolution calls Pfizer's current pricing structure unsustainable and harmful to U.S. consumers and governmental units.

Hatch questioned whether Pfizer's anti-import efforts are legal.

He said pension funds as shareholders have an obligation to "restore corporate responsibility" and protect the companies from legal liabilities.

The resolution also asks the company to report what it spends on lobbying, legal fees and consulting fees to protect its pricing structure.

A Pfizer spokesman did not immediately return a call seeking comment Wednesday morning.