A UBS entity has purchased the land under the Sports Illustrated Building for $279 million, The Post has learned.

The Swiss bank already owned the long-term operating lease and, sources said, intends to keep the property at 135 W. 50th St.

The purchase of the land was made through the UBS-controlled TPF Operating REIT on Aug. 14, documents show.

TPF obtained the lease in 2008 through an internal UBS transfer from Aetna Life Insurance, according to the paperwork.

The seller, 14 E. 60th St. Associates, is made up of managing member Suzanne Lehmann, who inherited the interest from her father, and since 2008, included the Zev Wolfson family, which bought its interest for $56 million from the Peter Jay Sharp Foundation.

Wolfson, whose entities also own One State Street Plaza and 25 Broadway, both downtown, died at age 84 on Aug. 13, the day before the sale closed.

Lehmann had signed the documents on Aug. 10.

Wolfson, his family and foundations had invested with Ponzi schemer Bernie Madoff, and now trustee Irving Picard is seeking “clawbacks” where monies received were more than what had been invested.

Sources tell us that Brad Siderow of the Siderow Organization, who represented UBS in the 2006 transaction, was also involved in this transaction while Darcy Stacom and Bill Shanahan represented the sellers of the land and David Werner provided additional advice to the Wolfsons.

Murray Hill Properties bought the 1964-era lease in 2004 for $143 million after negotiating an extension to 2106 that included a right of first offer for the land. Murray Hill sold it to UBS in the frothy market of 2006 for $332.5 million but remained as manager and leasing agent and is expected to continue in that role.

None of the calls or e-mails to the various parties were returned and Lehmann could not be reached.

Tenants in the 800,000 square-foot-office building include Time and Alliance Bernstein investments.