Billing, who is currently Director of Trade and Partnerships, will assume responsibility for a new loyalty brief, overseeing the development and launch of Riviera's new loyalty initiative.
Riviera is currently developing its own dedicated loyalty platform, which will feature dedicated strands for both travel agents and also direct customers.
It said Billing's new role reflected both the growth in Riviera's business through the trade, and "the increasing importance of loyalty as a key pillar in the brand's future strategy".
Docherty, meanwhile, sees her Head of Trade remit extended to include Ireland as well, with Carrie Day, Country Manager for Ireland, now set to report into Docherty, who will continue to report into Billing.
Riviera said Billing's promotion would bring trade engagement, partnerships and loyalty under a single leadership structure, while Docherty's would strengthen its trade focus and leadership structure in Ireland.
Matt Luscombe, Riviera Travel's Chief Executive, said: "As Riviera continues to grow, it’s important we evolve our leadership structure to support the next phase of our ambition."
He credited Billing for playing a pivotal role in shaping Riviera's trade strategy, strengthening its partnerships and delivering commercial growth. "Her expanded remit reflects both the impact she had made across the business and the strategic importance of loyalty as we continue to enhance the experience we provide to our trade partners and customers," said Luscombe.
Of Docherty, Luscombe added she had established herself as "a highly respected leader within the business and across the trade". "Expanding her responsibilities to include Ireland allows us to build on that success, bringing even greater focus and consistency to two strategically important markets," he said.