Plans to alter aircraft flight paths that cross the region have been postponed because passenger numbers have failed to reach expected levels.
Air traffic control organisation NATS said any new changes north of London will be included in a wider review.
NATS looked at air traffic in an area stretching from the Norfolk, Suffolk and Essex coasts to Cambridge and Milton Keynes down to the River Thames.
Traffic downturn since 2008 has reduced the urgency for immediate change.
Current forecasts show air traffic levels are not expected to return to the peak levels of 2007 until at least 2013/14, according to NATS.
Routes across the region are linked with major airports including Heathrow, Stansted, Luton, London City, Southend and RAF Northolt.
Alex Bristol, NATS development and investment director, said: "We are already working on a wider project involving the airspace over much of southern England.
"These include keeping aircraft higher for longer on more direct routes, which saves fuel burn and CO2 and means less noise for people on the ground.
"Whilst the downturn in air traffic means we can take longer to ensure we have the best solution, we have always been clear that doing nothing is not a long-term option."