Transport group Go-Ahead has apologised to passengers dogged by delays on its train lines as it delivered a robust half-year performance.
The bus and train operator said it is "working hard" to improve the service for commuters on its Govia Thameslink Railway (GTR) and Southeastern lines, but said many of the causes for underperformance were outside its "direct control".
The services - which include Gatwick Express, Great Northern, Southern, Thameslink, as well as the Southeastern franchise - have been hit by signalling and infrastructure woes alongside problems caused by the redevelopment of London Bridge.
Go-Ahead has already come under fire after its Southeastern and Thameslink and Great Northern services finished bottom of a passenger satisfaction survey by consumer group Which?
Chairman Andrew Allner said once the problems were addressed on the GTR and Southeastern lines, he is confident it will see a "dramatically improved service for passengers".
The group's apology came as it reported pre-tax profits rising 17% to £52.1 million for the six months to December 26 2015.
Go-Ahead - which runs around 4,600 buses for nearly two million passengers - saw bus adjusted operating profits rise 1.5% to £47.8 million over the period.
But its London bus operation faced a few bumps in the road after problems with roadworks and congestion caused the division's adjusted operating profit to fall 4.4% to £21.7 million.
Its rail business saw a 62% surge in adjusted operating profits for the half year, coming in at £32.9 million.
Shares in the FTSE 250-listed group soared 7% after the results.
Group chief executive David Brown said the company was "pleased to report a solid set of results for the first half of the financial year".
But he said: "We share the frustration of customers who have recently experienced disruption to their journeys.
"Together with Network Rail, we are committed to minimising the impact on passengers," he assured.
The group said it was boosted by a string of new contract wins for its rail and bus services, including a 25-route bus contract in Singapore and two rail contracts in Germany.
The company announced in September that it would miss its longstanding £100 million bus earnings target by a year, blaming a weaker economy in the North East and roadworks in the South.