A quarterly financial report released Friday shows that sales from Cal Athletics’ Endowment Seating Program have not kept pace with initial projections.

At the end of last year, Cal Athletics sold 1,873 seats of the 2,902 total ESP inventory, with 19 in the process of being sold.

While the dollar value of these seats amounts to $151.3 million, the campus had collected a total of $43.7 million in seat payments due to the fact that a majority of pledge agreements provide for payment over time.

“The main problem was that we overestimated the amount of seats that would be sold after the new stadium was opened last fall,” said Vice Chancellor of Administration and Finance John Wilton.

Since the last quarterly report was released, only 15 seats have been sold. While Cal Athletics originally predicted that all ESP seats would be sold by June 2013, new projections assume that seats will sell at a rate of 70 to 120 per year.

Cal Athletics issued $276 million in long-term debt for the safety retrofitting of Memorial Stadium and has yet to issue a remaining $45 million. Interest-only payments are due until 2032, 2033 or 2038, depending on bond issuances, explains the report.

The original plan was to use ESP funds to provide a large portion of the debt repayment. However, suboptimal sales have prompted Cal Athletics to consult with professors Richard Stanton, Nancy Wallace and William Fuchs from the Haas School of Business to revise their strategy to maximize additional sources of revenue to supplement repayment funds.

“We realized we needed to take a slightly different approach,” Wilton said.

Changes to the ESP model include the sale of new corporate seating “bundles,” which allow short-term purchases of a customizable number of seats. Existing ESP members have also been given the option to purchase discounted “perk” seats for a single game or season.

Additional revenue streams include income from the rental of newly refurbished facilities and additional sales of multimedia and sponsorship rights after the expiration of Cal Athletics’ contract in 2017.

Some aspects of the initial financial plan that troubled critics have been left in place, including the fact that those purchasing ESP seats are under no contractual obligation to renew payments. Other criticisms of the plan have included concerns as to whether patrons will remain interested in owning seats should Cal’s team continue to have difficult seasons.

“Yes, the team’s performance will always have an impact on ticket sales, but unfortunately, we can’t control the football team,” Wilton said. “In the end, we’re talking about projections, and the one thing that’s 100 percent is that these numbers will be wrong.

“I think that these new targets are as realistic as we can be at this point.”