Knowles is the father of Destiny's Child lead singer Beyoncé.
Another former group member Kelly Rowland left thecamp last year.
"From my time in Destiny's Child to my solo career, I am gratefulfor everything Matthew and his team has done for me," Williams said in astatement. "We've shared great success together. However, as I move in a newdirection in my career, I felt it was time. I wish Matthew Knowles and theMusic World Entertainment family all the best."
Ironically, when Rowland announced her departure fromKnowles management company last January, the publicity teams for both partiesreleased a joint statement.
In December, TMZreported that Knowles' wife, Tina, filed for a divorce.
Williams recently starred in Chicagoin London. In 2003, she made her Broadway debut playing the lead role inDisney's Aida. In 2007, she toured as a cast member of the musical The ColorPurple.
Williams released her first solo pop album, "Unexpected," last year. The lead single "We Break The Dawn" is a good song. I was surprised that the track and album received little promotion.