The Ivory Coast Democratic Party said Thursday that it was suspending its participation in the unity government.
A member of the Democratic Party said it was pulling out because of a dispute with President Laurent Gbagbo over the Abidjan port authority.
The port, once run by the Democratic Party's former president, is currently in the hands of the president's appointee.
Cabinet appointments in Ivory Coast have been a frequent cause of friction among members of the unity government, which was set up a year ago to bring together rebel and government factions.
Meanwhile, the rebels, who control the north of Ivory Coast, stayed away Thursday from a meeting to lay the groundwork for disarmament, which is scheduled to start March 8 The rebels said they disagreed with that date.