FedEx Freight (FDXF) will join the Dow Jones Transportation Average, effective Monday, replacing American Airlines Group (AAL), S&P Global (SPGI) division S&P Dow Jones Indices said late Wednesday.

Parcel giant FedEx (FDX) is spinning off FedEx Freight in a transaction expected to be completed Monday, according to S&P Dow Jones.

American Airlines has a "low weight in the index of less than one-half of one percentage point caused by its low share price," S&P Dow Jones said.

American Airlines shares were down 1.4% in premarket activity Thursday, while FedEx rose 0.1%.