Yale University’s famed endowment has been trying to offload one of the largest portfolios of private equity investments ever in a single sale, a move that reflects the pressures on both Wall Street and higher education under the Trump administration.

The Ivy League school has sought buyers for up to $6 billion in stakes in private equity and venture funds, according to three people briefed on the sales process, amid uncertainty about its federal funding and the reality that many of these investments have not delivered the outsized returns that Yale had come to expect.

Yale is now close to completing a sale of roughly $3 billion of the portfolio and is selling the assets at a slight discount, one of the people said.

“This is a big deal,” said Sandeep Dahiya, a professor of finance at Georgetown University, who has conducted research on the performance of endowments. “The investor that was the lead architect of investing in the private equity markets is pulling in its horns.”

For decades, Yale has been regarded as a pioneer for shifting its investments away from stocks and bonds into longer-term holdings managed by private-equity and venture-capital firms. But last year, Yale’s $41 billion endowment generated returns of just 5.7 percent, underperforming the S&P 500 and other major indexes. Yale said its 10-year return is 9.5 percent.

Private-equity investments typically generate cash for endowments and other investors after they sell or take public the companies in which they have invested. But lately, private-equity and venture firms, which make up about half of Yale’s endowment, have struggled to sell their stakes in companies and return cash to investors. That has driven down returns.