Arriva Cymru is making changes to the X94 Barmouth-Dolgellau-Bala-Corwen-Llangollen-Wrexham bus service after last operation on Saturday, March 9.
From March 11, Arriva has said that it can no longer operate evening services.
Arriva currently runs these commercially (without the benefit of a public tender) and revenue is no longer covering the costs of these journeys.
The Welsh Government and Denbighshire and Gwynedd Councils have sought expressions of interest for a replacement evening service.
Tenders have now closed but the responses are still subject to evaluation.
This process will include the likely cost per passenger given usage in the evenings. Passenger transport budgets are already under pressure at both authorities.
Once evaluated, members of both Councils will need to consider whether the deficit after any Welsh Government funding represents value for money.
There are no substantial changes to daytime services from 11 March, although some journeys are retimed and the earliest departure at 0458 from Dolgellau to Wrexham, very recently introduced, will be withdrawn.
Services will continue to operate via the villages of Cynwyd, Llandrillo and Llandderfel. This includes any evening service replacements.
The Sunday service, operated by GHA Coaches, is unaffected.