49 U.S.C. § 41502

1. (a)An air carrier may establish reasonable joint prices and through service with another carrier. However, an air carrier not directly operating aircraft in air transportation (except an air express company) may not establish under this section a joint price for the transportation of property with a carrier subject to subtitle IV of this title.
2. (b)For through service by an air carrier and a carrier subject to subtitle IV of this title, the participating carriers shall establish—
   1. (1)reasonable prices and reasonable classifications, rules, and practices affecting those prices or the value of the transportation provided under those prices; and
   2. (2)for joint prices established for the through service, reasonable divisions of those joint prices among the participating carriers.
3. (c)An air carrier and a carrier subject to subtitle IV of this title that are participating in through service and joint prices shall include in their tariffs, filed with the Secretary of Transportation, a statement showing the through service and joint prices.