She was an advisory director of the Metropolitan Opera.
In 1983, he became an advisory director of the firm.
The move comes after advisory directors complained earlier this month about the lackluster performance of the firm.
"Phil just didn't make the sale," said one advisory director who insisted on not being identified.
He retired in 1989 as an advisory director.
He had a long association with the Metropolitan Opera, and became an advisory director in 1993.
He retired in 1972 but remained associated as an advisory director until his death.
He was named advisory director in 1975, a title he held at his death.
Mr. Brennan, 55, will become an advisory director, remaining active but reducing his time commitment.
He will become an advisory director with the firm, maintaining certain client relationships.