JetBlue and regional carrier Contour Airlines have begun an interline partnership.
Mixed itineraries can now be booked on multi-leg trips that touch the six airports served by both carriers: San Juan, Phoenix, Nashville, Chicago O'Hare, Dallas-Fort Worth and Denver.
Contour serves close to 40 destinations. Among other locations, the interline agreement will give JetBlue flyers access to Contour service from San Juan to the Caribbean island of Dominica.
Contour also serves several small markets from Charlotte, which is the airport from which it offers the most flights.
Contour also has interline agreements with Alaska, American and United.