CSX ( NASDAQ: CSX) remains open to an approach from Warren Buffett's ( NYSE: BRK.B) BNSF, but no offer has been made, according to CNBC's David Faber on Monday. There "have not been any talks of any kind involving an actual acquisition," Faber said on the business network. "They haven't been approached. They haven't gotten an offer at CSX."

CSX and Berkshire Hathaway-owned BNSF on Friday announced new coast-to-coast services, a move that strengthens their freight connectivity but that tempers market expectations of an imminent merger between the two rail giants.