CoStar taps European managing director as next CFO

Arlington County-based real estate and data analytics company CoStar Group has appointed Robin Rossmann to be its new chief financial officer, effective July 31.

Currently managing director of CoStar’s European operations, Rossmann succeeds Christian Lown, CoStar announced Monday. Lown is stepping down to become executive vice president and chief financial officer of Allstate, effective Aug. 3, the insurance company announced Monday.

As CFO, Rossmann will report to founder and CEO Andy Florance and oversee the company’s global finance organization, including financial and operational performance, capital allocation, financial planning and investor engagement. He joined STR in 2016 and became part of CoStar through its 2019 acquisition of the hotel data company.

In 2025, CoStar reported $3.2 billion in revenue, up 19% over 2024’s $2.7 billion. The company has 8,400 employees and 86 offices in 15 countries. Its websites attracted 131 million average monthly unique visitors during the first quarter of this year.

CoStar said Rossmann helped improve the profitability of its European business over the past two years by eliminating about $51 million in costs — roughly 25% of its European cost structure — while delivering double-digit revenue growth and launching operations in France.

“Robin is a rare executive who combines deep financial expertise with proven operating leadership and a demonstrated ability to dramatically reduce costs while accelerating growth,” Florance said in a statement. “During his time with CoStar Group, he has consistently delivered outstanding operating performance across our international businesses — driving strong organic revenue growth, expanding margins, successfully integrating acquisitions and launching our products in new markets.”

Before joining STR, Rossmann spent 13 years at Deloitte, where he was a senior director advising public and private real estate and hospitality companies in the United States, the United Kingdom and other international markets.

In a statement, Rossmann said CoStar “has built one of the strongest and most differentiated real estate technology companies in the world” and that he was honored to assume the role of CFO.

“I look forward to partnering with Andy, our leadership team and our employees to drive disciplined capital allocation, enhance operational efficiency, expand margins and support continued profitable growth while delivering long-term value for our shareholders,” he said.

Lown will step down as CFO effective July 31, after having taken the role in July 2024. He previously was executive vice president and CFO of Freddie Mac.

“On behalf of the board of directors and the entire CoStar Group team, I want to thank Chris for his contributions during his tenure with the company,” Florance said. “We appreciate his service and wish him continued success in his future endeavors.”

Rossmann’s replacement as European managing director has not yet been announced.

In May, CoStar announced plans to acquire homebuilding data and software firm Zonda for $800 million in cash. The company is also facing multiple federal antitrust lawsuits accusing CoStar of participating in monopolistic practices. CoStar has denied the allegations.