Carillion Powerlines has won an £11.6M Network Rail contract to deliver upgrades to stations on the Shotts line between Holytown Junction and Midcalder Junction.
The work is part of a bigger £160M project to electrify 74km of the route between Glasgow and Edinburgh.
Two stations, Livingston South and Breich, will be completely rebuilt. At Carfin, Shotts and West Calder, platforms will be extended. Work is due to complete in autumn next year.
Last year Carillion won the £49M contract to electrify the Shotts line between Holytown Junction and Midcalder Junction.
Network Rail route delivery director Iain McFarlane said: “This contract is another step forward for the delivery of the Shotts electrification project and further underlines our commitment to investing in and enhancing our infrastructure as part of our UK-wide railway upgrade plan.”