Thomas Properties Group was a real estate investment trust based in City National Plaza in Los Angeles, California.

[1] In August 2005, the company entered the Houston, Texas market with the acquisition of 2.5 million square feet of office space from EQ Office in a joint venture with CalSTRS.

[3] On July 1, 2007, Lehman Brothers and CalSTRS partnered with Thomas Properties to buy several properties in Austin, Texas that The Blackstone Group had acquired as part of its acquisition of EQ Office.

In 2012, the company, in partnership with CalSTRs, acquired Lehman Brothers's interest in the joint venture.

[7] Thomas Properties Group was recognized for leadership in greening real estate and in integrating sustainable design and operations into all aspects of its products, services and investments.