Scenic and Emerald Waterways has further extended its cruising and touring suspension until 31 August, but has pledged to protect agent commissions on cancelled bookings.
The latest advice applies to all river and ocean cruises, and land tours across the Scenic Group. All Scenic Eclipse sailings, meanwhile, have been suspended until 30 September.
Guests will be offered "flexible" future travel credits with up to three years’ validity, including a 10% rebooking bonus for guests booked on affected cruises.
Colin Downing, Scenic Group’s UK managing director, said: “Our top priority is to ensure our guests and employees are able to travel safely before we resume operations.
"Although we have seen some easing of national lockdowns, the restrictions on travel still vary considerably from country to country and it is sadly impossible for us to operate our scheduled departures up to 31 August.”