Universal Shipping lobbies for leniency against the Xenos.
I am sure they get money from Universal Shipping too, as only Universal shipping benefits from their hauliers being immune to attack while the foreign hauliers such as Gateway and Republican get attacked. Therefore, in return for a small amount of funding to the Xenos, the premiums on Universal Shipping transports are greatly reduced by Interspace Commerce, as they dont have to pay out insurance as much. Something like a "no claims bonus".
On the other hand, things being shipped into Liberty, as they are prey for the Xenos, can be sold at a good price. Things like Silver, Diamonds, Cardimine, Artifacts, Luxury foods and other raw materials are all needed, and an anonymous business man could sell the stolen wares and return the money to the Xenos.
The Xenos even directly raid bases and shipments arriving at their destination. I am sure the arms transport to Detroit munitions which was looted by the Xenos provided some profit.
