More than 1,200 bus drivers in Manchester are planning a series of 24-hour strikes in a protest over pay, union representatives said.
The firm says its bus drivers are among the best paid in the city
Stagecoach drivers in Manchester are to stage walkouts on 27 and 29 November and 1, 3, 5 and 7 December.
Bobby Morton, of Unite union, said the drivers had rejected a wage deal that would have left them behind the market rate for transport workers in the city.
A Stagecoach spokesman said its offer was "well in excess of inflation".
Mr Morton, the union's regional officer, said: "Our drivers at Stagecoach are well behind the going rate in Manchester and it's simply not good enough to be fobbed off with a two-and-a-half year deal which will see them slip further behind."
He said the drivers had rejected a 4.5% pay increase.
The union had then turned down a deal worth an extra 50p an hour for 15 months followed by a further 50p an hour for the next 15 months.
Mark Threapleton, managing director of Stagecoach Manchester, said the firm was "surprised and disappointed" by the union's reaction.
He said: "By any standards this is a very good offer.
"We are very disappointed the unions have felt it impossible to settle this deal without strike action, and are pushing ahead to unnecessarily inconvenience passengers who rely on our bus services, particularly at this time of year.
"Our rates of pay are among the best in Manchester and our overall employment package is extremely competitive, and stands in favourable comparison with other bus operators in the area."