Once the nation’s wealthiest foundation, Indianapolis-based Lilly Endowment now ranks ninth among its grant-making peers.

The endowment’s value fell 15 percent last year, to an estimated $4.8 billion—the largest drop among the 10 largest foundations in the country, according to a report published this week in The Chronicle of Philanthropy.

Lilly Endowment’s wealth is particularly volatile because it holds about 95 percent of its assets in underperforming Eli Lilly and Co. stock.

Both Lilly stock and the endowment have lost almost 70 percent of their value since peaking in 2000. At the time, Lilly Endowment was worth $15.6 billion, second only to the Bill & Melinda Gates Foundation.

In 2009, the Seattle-based Gates Foundation increased its assets by 13 percent, to $33.9 billion, maintaining its decade-long hold on the top foundation spot.

Lilly shares have swooned since the Indianapolis drugmaker lost patent protection for its blockbuster Prozac in August 2000. Almost four years ago, the endowment announced plans to diversify its holdings—and mitigate its risk—by selling $2 billion of Lilly stock. But as IBJ reported this month, it has sold only $390 million in shares so far.

Only two other foundations on the Chronicle’s Top 10 list lost value in 2009: the Ford Foundation in New York and the W.K. Kellogg Foundation in Battle Creek, Mich. Ford’s assets dropped 6 percent; Kellogg’s declined 13 percent.

The value of a foundation’s assets have a direct effect on its grant making, since tax laws require such organizations to distribute at least 5 percent of their holdings each year.

Endowment spokeswoman Gretchen Wolfram told IBJ she could not disclose the total value of gifts approved in 2009 until the organization's annual report is released next month, but she acknowledged that grant making declined last year.

Despite the drop in assets and rank, "we still consider ourselves an important and large foundation," Wolfram said.

Microsoft founder Gates’ foundation approved $3 billion in grants last year, according to the Chronicle report. Ford Foundation, which ranked second with $10.5 billion in assets, approved $482 million in grants.