By Jeremy W. Peters

ALBANY — To cope with a growing number of retiring baby boomers and a shrinking state pension fund, the state comptroller said on Monday that he would ask the Legislature to permit a larger share of state pension assets to be placed in less-traditional investments.

The part of the pension fund that can now be placed in such investments, like private equity and hedge funds, is 25 percent.

But the comptroller, Thomas P. DiNapoli, said that those restrictions limited the state’s options for increasing the fund’s assets at a time when more traditional investments like domestic stocks are experiencing volatility and the pool of retired state workers is expanding by the day.

“We need some more flexibility,” Mr. DiNapoli said at a news conference. “We need to have our investments be guided in part by prudence and smart investment decisions rather than by prescription.”

Mr. DiNapoli sought the change from the Legislature as he announced that the pension fund had had a 2.6 percent return on its investments in the fiscal year that ended on March 31.

The fund’s assets are now $153.9 billion, making it the third-largest pension plan in the country. That is down slightly from a value of $154.5 billion in the previous fiscal year, meaning that even though the fund performed well, its gains were not enough to keep up with the growing number of retirees who are drawing pensions.

The number of retired state workers rose 2.3 percent from the last fiscal year, and is expected to continue rising.

Mr. DiNapoli provided an overview of the pension fund’s performance showing that its assets had held up despite turmoil in financial markets this year. While the fund’s domestic stocks took a beating — losing 6.4 percent of their value — that was the only segment of the fund that declined.

Its strongest earners were private equity funds, which rose by 24.8 percent, and real estate investments, which grew by 14.8 percent. Mr. DiNapoli said that if the state had not been limited in how much it could invest in those categories, the fund’s growth would have been greater.

“We could have easily maximized our returns closer to 4 percent,” he said. Allowing the fund more flexibility, he said, “would be a sound move for the state.”

He said that he could not yet suggest the amount by which the cap on alternative investments should be increased. But he said he would not be asking for carte blanche.

“I have not finalized what our proposal would be,” he said, adding, “Obviously we’re not going to look for the freedom to do whatever we want.”

Exactly how the Legislature would respond to Mr. DiNapoli’s request was unclear. A spokesman for the Assembly speaker, Sheldon Silver, declined to comment. A spokesman for Dean G. Skelos, the Senate majority leader, said that Mr. Skelos did not have a position on the proposal because Mr. DiNapoli had not yet discussed it with the Legislature. “We’ll take a look and see what he’s proposing,” said the spokesman, John McArdle.

This is the second time in two years that the Legislature has been asked to consider raising the percentage of the pension fund that can be invested in alternative investments. In 2006, it raised the amount to 25 percent from 15 percent.