Mlive.com and TV stations WXMI and WZZM say officials of Gerald Ford International Airport and the Regional Air Alliance of West Michigan will participate in the announcement. It's scheduled for 11 a.m. at the airport.
The Associated Press left a phone message Sunday for airport management.
The airport now has seven airlines. Passenger traffic fell 6 percent last year to 2.13 million passengers.
The Regional Air Alliance was instrumental in bringing Frontier and AirTran to Ford airport.
Southwest bought AirTran in 2011. Mlive says airport management won't say if Monday's announcement involves Southwest, which releases its new schedule Monday.
Ford Airport: http://www.grr.org/index.php