Kelly Hart & Hallman officially opened the doors of its Houston office this week. It's the first major expansion outside of its hometown for Fort Worth's largest law firm.

The firm hired as partners James Derrick, David Hedges, Max Hendrick and J. Clark Martin, all former Vinson & Elkins attorneys, to work in the office along with an associate.

More hires are planned, said Dee Kelly Sr., one of the firm's founders. The office has space for 21 attorneys.

After the hiring of former appeals court Judge David Keltner, Kelly Hart & Hallman announced that it planned to expand to a Houston office.

The firm has about 100 attorneys in Fort Worth and a client list that includes American Airlines, the Bass family interests and Pier 1 Imports.

Although the firm also has an Austin office, this is the first time Kelly Hart & Hallman has expanded in an effort to develop clients in a new area, Kelly said. Houston is home to several large energy-related companies along with other major corporations.

"I think it has a chance to succeed or I wouldn't have done it," Kelly said.