Billingham oversaw the commercial launch of Bristol Sport in 2014. Formed to bring together the commercial interests of its associated clubs the company also managed the £45m rebuild of Ashton Gate.
Bristol Sport chairman Jon Lansdown said: “Andrew guided the successful launch of Bristol Sport as we united our group of football, rugby and basketball clubs to have their commercial departments managed centrally.
“Since the completion of the redevelopment of the stadium last year, we have seen both Ashton Gate Ltd. and Bristol Sport flourish. In order to drive both businesses forward we have restructured to reflect the operating environment. Martin Griffiths has moved across, from chairman of Bristol Sport, to become chairman of Ashton Gate.
“I have stepped up into the role Bristol Sport chairman, after being vice-chairman for the last three years.
“Both Martin and I would like to thank Andrew for all his hard work and wish him well for the future.”
Andrew Billingham added: “It’s been a privilege to lead Bristol Sport through its launch phase and I’ve enjoyed my time in Bristol. The South West has become my adopted home and will always hold a warm place in my heart.
“With record attendances and a fully integrated commercial model supporting the £45m stadium redevelopment, Bristol Sport is set for success.
“I would like to thank my amazing team for their dedication and hard work and all of our business partners and supporters that have embraced a new beginning for sport in Bristol.”
