Transport operator Go-Ahead has hailed the achievement of a profit target set for its bus business four year ago – but apologised to passengers for the performance of its troubled Southern rail franchise.

Go-Ahead posted a pre-tax profit of £99.8m for the year to July 2, an increase of nearly 27% compared with the previous 12 months, on revenues 4.5% higher at £3.361bn.

The group’s regional bus division, which in East Anglia includes the Hedingham, Chambers, AnglianBus and KonectBus businesses, achieved a record operating profit of £53.3m, up from £48.7m.

And an operating profit of £47.1m at its London bus division, up from £44.3m a year ago, meant that the group just met the £100m target set for its overall bus operations in 2012.

“Our sector-leading margins, and the achievement of our £100m target, are a reflection of the hard work at our operating companies,” the group said.

“The business is maintaining its strong position by focusing on improving the service, stimulating passenger growth and developing relationships with local authorities.”

The group’s rail division, which also includes the Southeastern and London Midland franchises and is operated by Govia, a joint venture with French group Keolis, reported an operating profit of £57m, up from £41.7m.

Go-Ahead chief executive David Brown, who has declined a pay rise in light of delays and cancellations on Southern services, said: “We apologise to the people whose lives have been affected during this time. We continue to work closely with the Department for Transport, Network Rail and other suppliers and partners to operate the best service possible.”