Veteran Boston commercial real estate broker Kathleen C. Doyle is stepping down from the Boston real estate services company she co-founded 15 years ago with partner Catherine H. Thompson, according to industry sources.

Launched amid the recession that lingered in the early 1990s, GVA Thompson Doyle Hennessey & Stevens survived to become among the area’s strongest independent operations. Today, the firm offers a deep brokerage pool and coverage in both downtown and suburban markets.

During Doyle’s tenure at what was for many years Thompson & Doyle Co., the Brighton native brokered corporate deals in excess of $425 million and handled such major assignments as BioSquare, the ambitious medical research development alongside Boston University Medical Center in the Hub’s South End. Besides completing an intense leadership course at the Massachusetts Institute of Technology and serving as the leader of her firm’s life sciences division, Doyle is a Certified Commercial Investment Member and has been active in the Greater Boston Real Estate Board and the Massachusetts Alliance for Economic Development. She also is a former president of the Commercial Leasing and Investment Committee, now known as the Commercial Brokers Association.

Offering a focus on teamwork and broker training, Doyle and Thompson increasingly attracted several talented partners, including John F. Hennessey, Donald Hause, Debra Lee Stevens and Mark A. Stevens. The firm also formed an affiliation with GVA Worldwide to service clients internationally and recently relocated from its longtime home on Federal Street to 125 Summer St. in Boston.

Calls to Doyle and officials at TDH&S were not returned, but one source said the co-founder will retain a consulting role with her corporate creation.