CHICAGO — Chicago’s O’Hare International Airport will offer a transfer bus so passengers who are connecting to international flights won’t have to go through security again.

The Chicago Department of Aviation announced the service on Monday with American Airlines. The bus will take ticketed passengers connecting from American domestic flights to the international terminal via a secure part of the airport. That means the passengers won’t have to be re-screened before boarding their international flights.

Chicago aviation officials estimate the service could reduce the number of people going through security in the international terminal by as many as 1,000 per day.

The service will run from 10:30 a.m. to 8 p.m. during spring, summer and early fall. It will be for American passengers, or about 60 percent of passengers connecting from domestic to international flights.