U.S. Magistrate Judge Tonianne J. Bongiovanni on Monday granted Gov. Jon Corzine's motion to join the lawsuit. The suit was filed in March by state Sen. Raymond Lesniak, a Democrat from Union.
It argues that the ban puts New Jersey at an economic disadvantage relative to the states where it's allowed. Delaware is one of four states where some form of sports betting is legal.
New Jersey officials believe legalizing it here would provide a boost for Atlantic City's slumping casino industry.
The judge directed the governor to file his complaint by Nov. 12.
Information from: The Press of Atlantic City, http://www.pressofatlanticcity.com