The market value of the Hawai'i Employees' Retirement System's assets slipped by $634 million in the January-March quarter as pension plans across the country navigated turmoil in investment markets.

Rod June, ERS chief investment officer, said the pension plan had a minus 5.1 percent return during the quarter as assets declined to about $11 billion.

"These have been very difficult investment markets," said June, noting that investors saw declines in stock and fixed-income investments during the quarter. Still, the ERS did better compared to peers, beating the median return of minus 5.2 percent during the quarter for public funds with more than $1 billion in assets.

"We're not the only ones getting hurt here," June said.

The pension plan also did better than similar funds in the year ended March 31, earning a 2.5 percent return versus the median gain of 0.5 percent.

The ERS is Hawai'i's largest pension plan, providing retirement benefits for state and county workers.

It employs investment advisers to manage investments in stocks, bonds, real estate and other vehicles and tries to achieve an 8 percent annual return on its portfolio.

The end of the ERS' fiscal year is the end of this month. June said it appears the fund won't meet its benchmark return this year, since it would be difficult to achieve the 8 percent target in the next several weeks.

Even with the decline in assets the ERS has more than enough money to provide retirement benefits for members, he said.