Chief commercial officer Squirrell joined Titan in 2003 and has gone on to hold a number of senior roles within the business. A search for his successor is under way, Saga confirmed on Friday (14 November).
"It was an incredibly difficult decision to leave the business, but it is the right time for me now to pursue new opportunities," said Squirrell.
"I'm incredibly proud of my time at Titan and Saga, where I've had the privilege of working alongside such talented and committed people."
Nigel Blanks, Saga Travel chief executive, hailed Squirrell's commitment to agents during his lengthy spell with Titan and throughout the wider Saga business.
