Greg Leisch, a 48-year commercial real estate veteran and a D.C. market research leader, will retire at the end of the year.

Leisch, now a senior managing director at Newmark Knight Frank, announced his retirement in front of hundreds of industry professionals during NKF's annual Benchmarks event Wednesday evening at the National Portrait Gallery.

One of the most well-respected voices in D.C. commercial real estate, Leisch founded research firm Delta Associates in 1980 and led it until he joined NKF in 2015. Prior to founding Delta Associates, he provided real estate consulting and business research to clients of Gladstone Associates.

The announcement came as a surprise to the audience at the end of Leisch's trademark 30-minute market overview presentation. He thanked his wife, his colleagues and the entire D.C. commercial real estate industry.

"The commercial real estate market here is the best and most predictable in the country, so I thank all of you here for your business, and more importantly, for your friendship," Leisch said.

Following his announcement, NKF's Ryan Miller, Ed Clark and Bethany Schneider presented Leisch with a special award honoring his career and played a tribute video featuring several leading D.C. real estate figures praising Leisch and his accomplishments.

"When I think of Greg, I think of him being the authority on the real estate industry here in Washington, D.C.," Boston Properties Senior Executive Vice President Ray Ritchey said in the video.

Following Leisch's retirement, NKF Senior Managing Director Sandy Paul will take his place leading the firm's D.C. market research team. Paul also spoke at the event, interviewing Maryland Sen. Chris Van Hollen in the night's keynote discussion. Also honored at the event was MRP Realty Managing Principal Bob Murphy, who was given a Lifetime Achievement Award.