PORTLAND – Maine’s fund for retired state employees lost $10 million by investing in Enron Corp., the system’s executive director said Wednesday.

While the losses are significant, they represent just over one one-thousandth of the $7 billion pension system’s assets.

Trading of Enron stock, the Houston-based energy trader that filed for bankruptcy in December, recently was frozen at 67 cents. The price plummeted from as high as $83 last year.

“Unlike people whose life savings went away because of Enron, the losses for us were relatively small,” said Kay R.H. Evans, executive director of the Maine State Retirement System.

Bert Smoluk, an assistant professor of finance at the University of Southern Maine, agreed, saying the pension fund’s experience with Enron shows the importance of diversification for investors.

“It sounds like the retirement system didn’t have a very large position in Enron,” he said. “That’s the effect of diversification. You want to spread your money out as much as possible, so a significant loss in one company doesn’t affect your portfolio that much.”

The state retirement system provides pensions for 30,000 retired state workers, teachers and other former school employees.

Evans added that several retirees have called the state retirement system’s offices to express concerns that they will lose pension benefits because of Enron’s collapse.

Pensioners would not have been affected even if the system’s losses had been greater. Retirement benefits depend on factors such as the number of years employees worked and their earnings, not fluctuations in the markets.

Of course, a wider collapse of U.S. financial markets could affect the system’s overall solvency.

Maine’s system had invested in Enron through bonds and two index funds, according to Evans. Index funds pool investors’ cash to invest broadly in the stock market.

The retirement system liquidated the Enron holdings by the end of November, Evans said.

Nationwide, public retirement funds lost more than $1 billion from the Enron collapse. Officials from Georgia, Florida, New York, California, Ohio and Washington are all vying to become lead plaintiffs in a class-action lawsuit aimed at recouping some of the money their pension funds lost.

Jeannie Mattson, a spokeswoman for Maine Attorney General Steven Rowe, said Maine has not sought to join the lawsuit.