Penn State University's endowment has declined in value by about 20 percent, or roughly $300 million, since June, a victim of the stock market drop that is stoking financial worries on campuses nationwide.

In an e-mail exchange this week, Penn State President Graham Spanier said the school's investment practices had prevented even larger losses this summer and fall.

"Our portfolio is diversified and has been conservatively managed, so our decline has not been as great as those of some other universities, or as severe as the market in general," he said.

The endowment had a market value of approximately $1.6 billion on June 30, Penn State spokesman Michael Bezilla said. The decline to roughly $1.3 billion that Dr. Spanier described in his correspondence with the Pittsburgh Post-Gazette is for the period ending Oct. 31, the most current estimate available, Mr. Bezilla said.

Unlike some universities, Penn State does not rely on its endowment to support its operating budget.

The state's largest university, with almost 93,000 students, does, however, use money from it for needs such as student scholarships, library and equipment acquisitions, and faculty support including endowed professorships, travel stipends and graduate assistantships, Mr. Bezilla said.

Markets can rebound, he said, and any loss experienced by Penn State's endowment will likely not be felt through the current fiscal year that ends June 30.

He said students "will not see a decrease in the dollar value of their scholarships this year," and in future years, Penn State "would do everything possible" to protect those aid levels.

Last week, Penn State administrators told university trustees that the school's overall financial condition is healthy despite the worsening economy. While the school is reviewing the status of credit markets, it is proceeding with all construction projects currently under way, Dr. Spanier said.

Penn State will not impose a mid-year tuition increase, and will face pressure to keep next fall's tuition increase to a minimum, Dr. Spanier said. It is undergoing belt-tightening that is likely to include less money for employee raises.

A number of schools in Pennsylvania and beyond report similar endowment drops. Among them is the University of Rochester, whose president, Joel Seligman, notified the upstate New York campus Monday of a roughly 25 percent decline in investments, the equivalent of a $425 million loss on its $1.7 billion value.

Nationwide, not since the 1970s have colleges encountered similar endowment losses, and even then, the drops occurred over 18 months instead of just weeks, said Matthew Hamill, a senior vice president with the Washington, D.C.-based National Association of College and University Business Officers. He said typical losses in endowment value are running around 25 percent since the start of July.

Such a decline would mean his organization's 800 member schools, whose combined endowments are worth $400 billion, may have lost $100 billion in just over four months, he said.

It's one more reason for angst on campuses already facing a tightened credit market, uncertainty about fundraising and fears that families in financial peril may opt to put a student's education on hold. Public schools like Penn State face the added concern of cutbacks in their appropriations as the state's economy worsens.

"With every major revenue stream that universities have, there is at minimum significant uncertainty about how strong that stream will continue to be," Mr. Hamill said.

Even so, he said, "colleges and universities are incredibly stable institutions. These are institutions that will weather this storm."

Earlier this month, Carnegie Mellon University, with an endowment of roughly $1 billion, notified the campus that its endowment investments had fallen by 9.5 percent from July through September. As of Sept. 30, Duquesne University's endowment value stood at $142 million, down from $166.5 million on June 30, university officials said.

The region's largest endowment belongs to the University of Pittsburgh, which has declined to release data on how it has fared in the market this fall other than to say losses were likely. As of the summer, the value of Pitt's endowment was put at $2.4 billion.