Christie told reporters at a news conference there will be a special primary held Aug. 13 to determine the candidates for the October balloting, Roll Call reported.
The governor said he had not decided whether to fill the vacancy temporarily.
The Washington publication said the Democratic primary will likely feature Newark Mayor Cory Booker and U.S. Rep. Frank Pallone Jr., with the winner expected to be heavily favored in the general election.
Roll Call said the election law is vague enough an interim appointee could have been designated through November 2014, but Christie headed off any challenge by rejecting that maneuver.
"This is about guaranteeing the people of New Jersey both a choice and a voice in the process and the representation that they deserve in Washington," Christie, a Republican, said.
"I firmly believe that the decisions that need to be made in Washington are too great to be determined by an appointee for a period of 18 months."
Lautenberg, a Democrat, was the oldest member of the U.S. Senate when he died Monday of viral pneumonia at age 89.
He had announced in February he would not seek re-election in 2014.