Artistic director Stanton Welch hired Gielgud, his mentor at Australian Ballet, when he joined Houston Ballet in 2003.
"During this critical two-year period of transition from one artistic director to another, she played an important role," said Welch in a statement released by the company. "We recognize her significant contribution in Songs of a Wayfarer, which premiered at our gala performance in December 2004, Suite en Blanc, and Giselle. We wish her all the best in her continuing career."
But Gielgud told the Houston Chronicle that she and Welch had clashed over Gielgud's place in the company.
"It has been increasingly difficult to understand where his vision lies, what his goals are," she said.
Most recently, Gielgud and other sources at the company told the paper, Welch nearly canceled Gielgud's production of Giselle, scheduled for next season, and then changed her casting.
Welch told the paper that "there were different expectations regarding the scope of [Gielgud's] responsibilities." He also suggested that she was no longer needed after the hiring of other staff members.
"I'm sad to see Maina go, and I wish her all the best, but I certainly don't think it's going to damage the company," he added.
Gielgud danced with Roland Petit's Ballets de Paris, Maurice B_jart's Ballet of the Twentieth Century, and the London Festival Ballet in the 1960s and '70s. She directed Australian Ballet from 1983 to 1996 and the Royal Danish Ballet from 1997 to 1999. In 2000, she was appointed artistic director of Boston Ballet, but she never assumed the post, resigning after the company fired several dancers against her will.
The Australian-born Welch joined the Australian Ballet as a dancer under Gielgud's leadership in 1989. He began choreographing for the company in 1990, and Gielgud made him resident choreographer in 1995. The appointment helped to launch an international career.
According to the Chronicle, Welch and Gielgud have known each other since Welch was five years old, when Gielgud danced with Welch's mother, Marilyn Jones.