The companies are part of a £100m fund aimed at boosting the number of visitors to the UK and tourism jobs over the next four years.
Representatives from the two firms, as well as ferry operator DFDS, hotel group Radisson Edwardian and holiday website Lastminute.com, met with Prime Minister David Cameron yesterday to launch the fund.
They have pledged to match £50m in government funds committed by the national tourism agency, VisitBritain.
The royal wedding and the 2012 Olympics are among events the firms hope will draw in tourists, with the new campaign fund aiming to attract one million extra visitors a year, an additional £2bn spent by tourists and the creation of 50,000 new jobs.
BA chief executive Willie Walsh said: “We look forward to playing our part in
welcoming people from all parts of the world to Britain as part of this partnership with VisitBritain to celebrate everything our country has to offer.”