Two technology startups that help commercial-real-estate owners and brokers manage their businesses are merging in a deal that will create one of the largest technology companies in the industry, valued at about $300 million.

VTS and Hightower Inc., both based in New York, are merging in an all-stock transaction, executives at both firms said. The deal was expected to be announced to employees Tuesday.

The merged firm, which will keep the name VTS and be led by VTS Chief Executive Nick Romito, will provide customer-management tools for owners of more than 5.5 billion square feet of commercial space in the U.S. and U.K.

Investors in VTS include Blackstone Group LP and Boston-based venture-capital firm OpenView. Among Hightower’s major backers are Bessemer Venture Partners, Menlo Park, Calif., and Thrive Capital, a venture firm led by Joshua Kushner, whose brother, Jared Kushner, is married to Ivanka Trump, the president-elect’s daughter.

VTS and Hightower executives declined to discuss the value of the two firms, which together employ about 275. People familiar with the matter said the merged company is worth about $300 million.