CHEYENNE - The executive director of the Wyoming State Retirement System said the market value of the system's investments has declined by more than 15 percent since the beginning of the year.

Executive Director Thom Williams said the market value of the fund's investments was $6.2 billion at the end of June. By the end of September, the value had dropped to $5.5 billion - a decline of $700 million.

Williams said the decline means the value of the fund has dropped more than 15 percent from January through the end of September.

But Williams emphasized that the state's retirement system is strong and that beneficiaries can count on receiving their pension payments.

"This is a difficult time for individuals and institutions," Williams said. "But unlike most individuals, we've got a much, much longer term horizon and greater staying power."

Williams said the retirement system is under no obligation to sell its investments and lock in its losses.

"We don't consider these realized losses by any means," Williams said. He said the system has cash on hand to pay its obligations without selling while markets are down.

"We are really adhering to our asset allocations, and we have providers who try to keep us in balance, so when the markets do return, as I think they inevitably will, we'll participate in that," Williams said.

Wyoming is not alone in seeing the value of its public employee pension accounts drop.

Colorado officials announced last week that the Public Employee's Retirement Association there had lost $10 billion in market value through mid-October. The fund had decreased from $41 billion to $31 billion since the beginning of the year.

The California Public Employees' Retirement System announced last month that employees could see their contribution levels increase if the fund's investments sustain their current losses of about 20 percent.

Michael Walden-Newman, chief investment officer at the Wyoming Treasurer's Office, said Monday that the latest figures on Wyoming's other investments also show unrealized losses.

As of the end of September, the total value of Wyoming's investments apart from the employee pension system had declined from their original purchase price of $10.9 billion down to nearly $10.6 billion - a decline of $322 million.

Figures showing the value of Wyoming's investments at the end of October won't be ready for a few more weeks, Walden-Newman said.

"I know that the first week of October was arguably rougher than the entire month of September, but we've had some fluctuations in the market since," Walden-Newman said.

"We're long-term investors, it's important to remember," Walden-Newman said. He said the state doesn't have to sell its investments and lock in any losses.

"We believe we have the best managers in the business helping us manage this portfolio," Walden-Newman said. "And we're paying them for using their expertise, and expect them to use that expertise in the best interest of the state."