Siemens, Fortress, Wabtec Said to Vie for Alstom US Signal Unit

German conglomerate Siemens AG, Fortress Investment Group and US train-equipment company Wabtec Corp.are among bidders in the final stage of the auction for Alstom SA’s US rail-signaling business, people familiar with the matter said.

The bidders have valued the unit at about $600 million, said the people, asking not to be identified because the process is confidential. There’s no certainty the deliberations will result in a deal as all bidders are still carrying out due diligence, they said.

The Alstom signaling business provides equipment used to manage traffic for railroads and transit agencies.

Representatives for Alstom, Siemens and ...