Stagecoach chief executive Sir Brian Souter said it was not experiencing the downturn in Scotland reported by FirstGroup.
Indeed, growth at its UK bus arm helped offset an earnings slump in its rail business as Stagecoach posted a 1.6% fall in underlying pre-tax profit to £202.5 million for the year ended April 30. Revenue rose 8.4% to £2.6 billion.
With all its rail franchises now qualifying for Government support, and further strong growth in its US intercity coach arm, investors pushed Stagecoach's shares up 13.7p to 263.5p.
This added some £78.9m to its market value, which now stands at £1.5bn.
Stagecoach's bus business outside London was the main contributor to earnings, posting a 6.3% rise in operating profit to £162.7m, helped by a 5.9% rise in income from full-price fares.
FirstGroup blamed a weak economy in Scotland and the north of England for a near 10% drop in earnings at its bus arm earlier this year.
But Sir Brian said: "Our Scottish companies held up well."
He said that its north of Scotland and Aberdeen-based bus businesses had been particularly strong and added: "The only place we are seeing weakness is north east England."
Stagecoach increased bus fares by an average of 5% in April to counteract the drop in subsidy for concessionary travel.
Sir Brian said: "We have been very careful about the fare box this year. Quite a lot of our competitors put double that and more in earlier in the year and got poor results."
FirstGroup has announced it will sell some of its bus business and Stagecoach confirmed it is looking at the portfolio.
Sir Brian said: "There could be some opportunities for us to buy some underperforming businesses."
Douglas McNeill, analyst at Charles Stanley, said: "Stagecoach take a relentlessly commercial approach to acquisitions.
"They don't mind taking on underperforming businesses – but only at prices that give plenty of upside if they succeed in fixing them."
Stagecoach has highlighted its turnaround of East London Bus Group, which it acquired in late 2010.
It posted a £13.5m operating profit for the year after a £5.9m loss in 2011. Things were tougher in its UK rail business, where operating profits plunged 44% to £27.1m.
This was due in large part to its East Midlands Trains franchise, which was losing some £5m a month until it qualified for Government revenue support in November.
Stagecoach has been shortlisted for the Greater Western and Thameslink rail franchises.
Its Virgin Rail joint venture is seeking to retain the West Coast Main Line route.
Bid expenses could top £10m in the coming year, it said.
In London, where it has 16% of the bus market, Stagecoach was last week hit by a strike by workers campaigning for a bonus for working during the Olympic Games, after similar awards were given to other transport staff. Sir Brian said he does not believe bonuses are justifiable.
But he added: "Do I think it is equitable that the bus drivers should get something when everybody is getting something? Yes, I do."
He maintained the payment should be made by Transport for London.
Sir Brian condemned plans for a strike ballot at its South West Trains franchise, arguing that a previous pay deal covered the Games period.
"We will not yield on that," he said. "A deal is a deal."
Stagecoach has announced a 10.2% increase in its final dividend to 5.4p, which will be paid on October 3.
FirstGroup declined to comment.