By Guy Taylor Heathrow Airport will fall behind rival hubs in the East should it fail to pursue plans for a third runway, the boss of Istanbul Airport has said. In an interview with City A.M. Selahattin Bilgen argued the Hounslow hub had “limited capacity” compared to Istanbul and may need to jack up airport charges to bring in more cash. It has in the past been embroiled in spats with airlines over the level it can set the levy, with both the UK’s competition and aviation watchdogs wading in. “I agree if Heathrow does not invest in the third runway, this will limit its growth and, by the way,…