Lessen raised $500 million in equity and debt to help finance the deal, valuing the firm at more than $2 billion. Monroe Capital and Invitation Homes Inc. were among investors participating in the funding.

Exclusive WMRE research details how sentiment on office real estate has shifted as a result of uncertainty on the long-term outlooks for the sector.

A sale could attract private-equity firms and value the closely held business at more than $10 billion, Bloomberg News reported Wednesday, though the plans are still in an early stage.