The brother and sister founders of Stagecoach are to stand down as the company announced a fall in revenues.
Sir Brian Souter, 65, will step down as chairman but stay on the board, while Dame Ann Gloag will retire completely.
The pair co-founded the company in 1980 and have seen it become one of the UK’s biggest coach and bus operators.
Sir Brian said that, at the age of 65, he wanted to pursue other interests and spend more time with his grandchildren.
Sir Brian, who donated £1m to the SNP during the 2014 referendum campaign, became a controversial figure in 2000 when he funded moves to prevent teachers discussing gay rights in schools in Scotland.
The failed “keep Section 28” campaign 19 years ago resulted in the organisers of this year’s Turner Prize ending a sponsorship deal with Stagecoach.
Sir Brian will be succeeded by his deputy Ray O’Toole, who will take over in January.
The family said they would continue as significant shareholders in the company.
The announcement comes as figures showed revenue dropped significantly as Stagecoach scaled back its interests over the past 18 months – from more than £1bn in the first half of last year to £800m in the most recent six-month period.
Dame Ann Gloag, who is currently ranked as Scotland’s richest woman, is a philanthropist with business and charity interests across the world.
Stagecoach’s humble beginnings
Sir Brian and Dame Ann started with a handful of second-hand buses in 1980, running inter-city services in Scotland, according to his official website.
Dame Ann and her husband, Robin, bought a school bus, while Sir Brian used his father’s redundancy money to buy two coaches.
Perth-based Stagecoach grew out of Margaret Thatcher’s deregulation of the bus industry in the early ’80s and has grown to become one of the UK’s biggest bus and coach operators, employing more than 24,000 people.
They later diversified into running trains. However, Stagecoach was disqualified from the UK government from running West Coast main line services with Virgin in April over concerns with the firm’s pension commitments.
Stagecoach is taking legal action over the decision.
They pulled out of the US in 2018 where they had been running bus services for more than 20 years after having to significantly write down the value of the operation.