Scotland's Transport Minister Keith Brown visited Hawkhead Station to review progress on the project and was told it was on track to be finished in December.
The news follows completion of extensive engineering works during a closure of the line from October 13-21.
Engineers have completed the install- ation of overhead line stanchions along the five-mile route, while the platform at Hawkhead has been rebuilt.
Sections of the track have also been lowered to allow the new overhead power cables to run beneath bridges on the line.
The electrification project is the first to be delivered under a new alliance between Network Rail and ScotRail.
By working together more closely and efficiently, Network Rail and ScotRail say they have been able to significantly reduce the cost of the project, which was originally estimated at £28m.
Mr Brown said: "The big winners from this £12m investment are passengers, who will notice a marked improvement in the performance of the service and see more seats on services.
"The wider network will benefit from the introduction of electric trains, which will mean improved services on the Canal Line and wider Ayrshire and Inverclyde network, and reduced emissions."
The Canal Line, designed by Thomas Telford, started life as a canal intended to link Glasgow with Ardrossan.
It was converted in 1885 by the Glasgow & South West Railway, but it closed in January 1983 as a through route to Kilmacolm. It reopened as a branch line in July 1990.