FirstGroup chief executive Tim O’Toole has said the group made “a very aggressive bid” to retain the ScotRail franchise last year, and has lamented the lack of transparency over the winning bid from Abellio.

Mr O’Toole, commenting on a half year where rail franchise revenue fell by £586million and operating profit by £13.6m compared with a year earlier, said he had no regrets about the group’s unsuccessful ScotRail bid.

“It was the most celebrated franchise in terms of awards when we were running it, we delivered a six per cent average growth rate for 10 years, and we put in a very aggressive bid of eight per cent growth over the next 10 years,” Mr O’Toole said.

“It is not as though we sat on our hands and thought this would just be handed to us. We can’t explain the Abellio bid, unfortunately because they are not a public company we will never get to see the numbers as we would if it was a different competitor.”

The Dutch-owned operator has had mixed reviews since it took over the franchise last April. Mr O’Toole commented: “The less I say about the current franchise the better.”

FirstGroup, which lost out in four rail bids last year, said the impending award of a new franchise on the Trans-Pennine route which it currently operates under management contract, was “a great opportunity.....plainly we are under the shadow of our record to date in the bids”.

The US-born chief executive said the debt-laden transport giant was on course to generate cash again when his three-year transformation plan completes in early 2017.

He said: “Overall trading for the group during the first half was in line with our expectations, with outperformance in some areas offsetting the more challenging market environment in others.”

The group’s biggest business, First Student in the US, had delivered a second year of contract pricing increases and cost efficiency benefits, moderated by driver shortages and fewer operating days.

First Transit had landed further contract awards helping to offset reduced Canadian oil sands activity, while Greyhound had launched a yield management system to help mitigate lower demand from cheaper fuel. Mr O’Toole said: “We think it puts us in a position to efficiently price existing demand and inspire interest in markets that have been neglected in the past.”

The UK bus operation, where Glasgow has seen the biggest investment of its kind in the Caledonian bus depot, is said to be maintaining turnaround progress despite mixed trading conditions and less concessionary travel.

The rail business reported financial performance “towards the top end of our expectations, underpinned by strong passenger volume growth”. Stripping out the lost franchises and one-off issues, revenue was said to be 0.8 per cent ahead.

Mr O’Toole said investors could now “see the building blocks” for a return to cash generation, adding: “They now want to see it delivered, they don’t want to see reasons why it can’t be delivered.”

Analysts at Liberum said: “The group appears to remain on course for the full year, when we believe the effects of the turnaround programme will be more evident.”

They said the group was trading at only 4.3 times earnings, a clear discount to its peers. “We believe this is unjustified given the recovery potential, although we accept this is masked in the short term by recent rail franchise expiries and management’s track record is far from conclusive.”

The shares closed up 2.6 per cent at100p.