Thousands of commuters faced travel disruption following a Thursday afternoon walkout by Glasgow Underground staff.
Underground workers want a better pay rise
Drivers, ticket collectors and safety workers took strike action over a pay award dispute between 1430 GMT and 1830 GMT.
The T&G union said it would hold a meeting to discuss plans for further possible action.
The workers have rejected a two-year pay deal worth an extra 5.9%.
T&G members have also voted for strike action over changes to holiday cycles.
Douglas Ferguson, Strathclyde Passenger Transport director of operations, said he was willing to hold further talks but added: "That is the final offer on the table for subway staff.
"Not all of our staff are TGWU members and we will attempt to provide a limited service during the strike period.
"We apologise for any inconvenience this industrial action will cause and advise passengers to expect disruption to normal services during this period."
Free replacement bus services have been provided between Shields Road station and St Enoch and between Govan and Partick.