International Airlines Group has lifted its forecast annual operating profit to £1.8 billion.

The upgrade from a previous forecast figure of £1.6 billion is expected to come as a result of Spanish budget carrier Vueling’s performance, improved margins at British Airways and Iberia returning to profitability.

BA’s operating profit is now expected to rise from £1.1 billion to £1.3 billion while Iberia’s recovery plan is “on track” with improvements expected.

IAG told investors on Friday that additional contributions were expected from growth at BA and Barcelona-based Vueling this financial year.

The company said it was heading for a business model that could sustain organic growth levels of 2%-3% beyond 2015, excluding contributions from Vueling.

The forecast came ahead of a report in the Sunday Times which disclosed that only 66% of BA’s long-haul flights departed on time from its Heathrow base in August, down from 75% a year earlier.

The figure was down to 63% in July, according to Civil Aviation Authority figures the newspaper said it had obtained.

Punctuality dropped to 48% on flights to Los Angeles in August while performance also suffered on flights to Singapore (51%), Hong Kong (58%) and Mexico City (55%).

BA blamed overcrowding at Heathrow, where it operates more than half of the airport’s total flights.

A spokesman said: “Temporary factors can result in short-term fluctuations in performance, especially at Heathrow, which operates at full capacity and where, as the largest carrier, we are disproportionately affected by bad weather and other disruptive events.”

He added that the airline’s August punctuality on flights to New York JFK marked a low point and had since improved. New aircraft joining the fleet would also help to improve time-keeping.