CHESTERBUS has withdrawn adult return tickets, making the cost of a round trip 30% more expensive.
A return ticket did cost £2 but since August 14 passengers have had to buy two singles at £1.30 each, so a return journey now costs £2.60.
One reader e-mailed The Chronicle describing the fare increase as 'extortion'.
But Stuart Hyslop, managing director of ChesterBus, said the extra revenue was needed to offset the increased cost of oil, tyres, electricity and the purchase price of vehicles.
However, he said there were still special offers, including a weekly ticket, a stored value card - which offers a 10% discount - and an all-day ticket with unlimited travel for £3.
In addition, a pilot scheme is being trialled on routes 21 and 9, to Vicars Cross and Pipers Ash respectively, with an all-day ticket specific to those routes costing £2.
Mr Hyslop said rival Arriva had increased the price of its single fares.
Meanwhile, the Transport & General Workers' Union is 'dumbfounded' by proposals to sell ChesterBus.
Speculation had been growing about its future since the council cabinet took a secret decision in June.
The firm, which has 78 buses and 125 staff, made a loss of £62,174 in 2004/05 after depreciation, although it continues to make an operating profit.
On Wednesday ChesterBus staff were told it was being sold to secure the future of the company and bus services.
In a message to council leaders, a union official said: 'We believe a new company would operate on a purely commercial basis and axe most uneconomical services that are currently run by ChesterBus.'
In a letter to the workforce, the leader and deputy leader of the council, Cllr Paul Roberts and Cllr John Price said: 'New investment is required to sustain the future of the company. The council does not believe that the long-term success of the business is best served by the company remaining under council ownership.'
