Chief commercial officer Jim Forward said Riviera had been delighted with the "particularly positive response" to the offers from the trade.
It has so far placed 27 European and worldwide river cruises on sale, plus eight European solo traveller sailings and 108 escorted tours covering all seven continents, including UK itineraries.
"Now is the time for agents to encourage their customers to look to the future and start planning their ideal holiday on a risk-free basis," said Forward.
Both offers have been extended to new bookings made up to and on 31 March 2021 after previously having been due to run to the end of February.
