But the London-listed company's upbeat results were marred by news it too faced industrial action as more than 3,000 of its West Midlands bus drivers voted to strike over pay, beginning March 16.

"National Express is sitting on mountains of cash and can absolutely afford to give a pay rise to its staff that reflects rocketing living costs. It needs to do just that," Unite general secretary Sharon Graham said in a statement.

A spokesperson for National Express West Midlands' said it was disappointed by the strike action and urged drivers to reconsider.

"We anticipate a very limited service running on strike days," the spokesperson said.

Shares in the public transport operator rose as much as 19.2% during the day as the company also resumed dividend payments for the first time since 2020.

National Express owns and leases buses and trains in twelve countries, with North America, Spain and Britain its largest markets by revenue.

The company said revenue from its UK coaches more than doubled, as more people used buses to travel to airports and other cities across the country.

Multiple sectors in Britain have staged industrial action, including British rail workers who have held several strike days, as inflation has hit multi-decade highs and living standards have worsened.

National Express, based in Birmingham, central England, in December added more than 50,000 seats across its network to prepare for an increase in demand caused by rail strikes.

Its research found that nearly 10% of the people who first used their buses during the rail disruptions continued to do so even on non-strike days.

The company declared an annual dividend of 5 pence per share. Annual group revenue rose 24% to 2.81 billion pounds ($3.37 billion) and surpassed 2019 levels.

Its UK business reported an underlying operating profit of 48 million pounds for the year from a loss a year earlier.

($1 = 0.8340 pounds)