"I am delighted to continue my tenure with this magnificent orchestra," Graf said in a statement.
Orchestra president Ed Wulfe said the extension, which comes a month after the orchestra posted a smaller-than-expected deficit of $800,000, was another sign of recovery. "Combined with our solid financial performance last season," he said, "Hans' contract extension speaks volumes about our organization's strength and stability."
The orchestra suffered through a contentious strike in the spring of 2003, and ran a budget deficit of $3.6 million for the 2002-03 season.
The Austrian-born Graf, a one-time music director of the Iraqi National Symphony, completed a term as the music director of the Calgary Philharmonic in 2003 and led the Orchestre National Bordeaux Aquitaine until earlier this year.