Xplore Dundee says it is having to cut some services because of a shortage of bus drivers.
The operator has announced it will make temporary timetable changes from Monday October 4, which will result in reduced frequency of some services.
The company says it is working hard to try and minimise disruption for customers.
It comes on the same day that a shortage of HGV drivers led to concerns over the availability of fuel – while there have also been issues over the supply of carbon dioxide.
Christine McGlasson, Xplore managing director, said: “There are various reasons for this industry-wide issue, including the ongoing challenges of Covid and self-isolation.
“[There are] issues with DVLA and recruitment, and a natural turnover of the workforce, compounded by stiff competition for driving jobs across various sectors, not least the haulage sector which is facing its own shortages.
“We are very reluctantly changing the frequency of some of our services in order to try and improve reliability across the network.
‘This is a short-term measure’
“We believe it is vital, above all, to ensure that our customers can rely on our service to get them to where they need to go as scheduled.
“I want to emphasise that this is a short-term measure and we hope to restore full frequencies as soon as the situation stabilises.”
The firm says passengers can find updated timetable information on its website and app, or at its travel centre.