Riverstone Residential Group said Thursday that it has relocated its downtown Dallas office from the Bryan Tower to the 56-story Renaissance Tower on Elm Street.

The company, a real estate management firm subsidiary of Consolidated American Services, has leased 62,402 square feet.

We have experienced more than 200 percent growth in the past two years,” said Terry Danner, chief executive of Riverstone. “As a result, we have increased our staff, which made it imperative to expand to one of downtown Dallas’ larger office towers.”

About 225 of the company’s workers will be moved to the Renaissance Tower.

The lease is one of the largest signed downtown so far this year.

During the first quarter of 2008, downtown office occupancy grew by almost 90,000.