Tishman Speyer Properties LP has blocked office real estate investment trust SL Green Realty Corp. from taking over Carlyle Group LP's lease at its 1 million-square-foot 520 Madison Ave. building in Manhattan, N.Y., The Real Deal reported.

SL Green and private equity firm Carlyle signed an estimated $100 million deal in August under which the former agreed to take over Carlyle's existing lease for nearly 120,000 square feet of space at the Tishman Speyer-owned property, in order to secure Carlyle as a tenant for its under-construction $3 billion One Vanderbilt office tower.

Tishman said it could not bring a competitor into 520 Madison Ave. as SL Green would sublease space in the building, coming into direct competition with Tishman's own leasing activities, the news outlet said, citing a rejection letter from the landlord to Carlyle.

In response, Carlyle filed a lawsuit on Oct. 16, arguing that the agreement does not bar it from handing over its lease to a company affiliated with a competing landlord, according to the report.

Carlyle's lease term at 520 Madison is set to expire in 2031. The 1.7 million-square-foot One Vanderbilt tower is scheduled to open in 2020.