(Peoria, IL) — Caterpillar’s overseas business is reportedly at the heart of the investigation into one of Illinois’ largest companies. Federal agents descended on Cat offices across central Illinois yesterday. Cat CEO Jim Umpleby says the raids may be tied to a Swiss affiliate, but he says it’s too soon to talk about the specifics. A number of reports say federal agents are looking into allegations that Cat avoided more than two-billion dollars in U.S. taxes.