Buoyed by a healthy stock market, university endowments posted robust earnings in 2004, but not enough to compensate fully for the losses of previous years and to enable the kind of spending that many institutions depend on to run their campuses, according to the most recent annual survey by the National Association of College and University Business Officers.

Endowments - the financial stockpiles that help determine an institution's financial health - brought in an average 15.1 percent return during the 2004 fiscal year. It was one of the largest average returns since the mid- to late 1990s, and it came as a huge relief after declines in 2001 and 2002, followed by only a modest rebound in 2003.

The survey credited the strong performance of stocks, bonds, hedge funds and other investments for last year's gains. But for all the good news, the survey also found that endowments still faced erosion from the combination of inflation and a widespread need to dip into the money.

"We're all pleased to see the good year," said Jessica M. Shedd, the association's research director. "But there's still a long way to overcome the difficulties we've faced."

Over the past five years, endowments have earned an average of 3.8 percent, the survey found. That is only slightly above the average rate of inflation over the same period, 2.7 percent, according to the survey. Beyond that, universities typically have to use some of their money to pay managers who orchestrate their investments. And, most significant, institutions spend about 5 percent of their endowments every year to run their campuses, making for an overall drain on endowments despite last year's strong returns.