Haynes and Boone office at 30 Rockefeller Plaza.

Haynes and Boone finance partner Craig Unterberg, the firm’s new office managing partner in New York, said his biggest challenge in his new role will be growing the 15-year-old office while maintaining the firm’s collaborative culture.

“It would be great to double it in size, but at the same time, we are committed to protecting our culture,” Unterberg said about his task for the coming years.

The office has grown to 70 lawyers since partner Kenneth Bezozo, who tasked his then-16-year-old daughter with hand lettering a Haynes and Boone sign, opened it in 2004. Bezozo managed the office until Unterberg moved into the role on Jan. 1.

Unterberg, 46, said the firm wants to expand in a big way in New York, simply to provide more service to clients. That office’s growth strategy has centered on the real estate and finance practices, he said, but the office also has lawyers in other areas, including litigation, restructuring and intellectual property. His plan is to continue to strengthen those practices as well as beef up corporate and M&A, all based on client demand.

Unterberg’s own practice involves lending work for hedge funds and private equity companies, with many of his clients based in New York and Texas. He moved from Haynes and Boone’s Dallas headquarters to New York in 2009 to help grow the firm’s presence in the Big Apple. He said he is optimistic about expanding the number of lawyers in New York, despite intense competition in the Big Law lateral partner market.

The firm’s move to transition the New York managing partner role is related to Haynes and Boone’s goal of moving midcareer lawyers into management, Unterberg said.

“It’s a real conscious effort, making sure the voice of different generations of the firm … are being heard,” Unterberg said, noting that he’s been working closely with Bezozo over the last few months in anticipation of taking on the management job.

Bezozo could not immediately be reached for comment.

Unterberg said he just rolled off as head of the finance section, an assignment he held for three years, which is another indication of the firm’s commitment to assigning younger partners to management roles. Houston partner Neal Kaminsky is now leading that section.

Haynes and Boone made one other change in office management this month. In Houston, partner Ricardo Garcia-Moreno is the new administration partner for the office, succeeding Mark Trachtenberg, who had that role for six years. Garcia-Moreno declined comment on his plans for the office.

Haynes and Boone has 13 offices in the U.S., as well as in London, Mexico City and Shanghai.