East Midlands Airport has won a nine-year fight to extend its runway despite concerns over night-time noise from jet engines.

The £4m scheme was approved by North West Leicestershire District Council, the planning authority last night.

Members of the planning committee voted unanimously in favour of the proposal – on the proviso that strict conditions are placed on night-time flying between 11pm and 7am.

They include a 55 decibel limit on jet engine noise at the outer reach of a 16sq km area around the airport.

The aim of the 620ft extension to the Castle Donington airport's 10,000ft airstrip is to allow heavier planes to take off – making the UK's third-biggest freight airport more attractive to long-haul cargo carriers, especially across the Atlantic.

Opponents objected to the scheme because they believe it will lead to more noise and air pollution.

Dr Paul Grimley spoke out on behalf of villagers under the flight paths, campaign groups and parish councils opposed to the extension. He said: "There will still be a 25% increase in night-time noise levels for people in the vicinity of the airport, which we are not happy about.

"While we are pleased that enforceable noise controls, which are overdue, will be in place for the first time, what we want is for a scheme for progressive improvements to further reduce noise levels over time."

Kegworth and Whatton Councillor Trevor Pendleton said: "This is not enough. Why not push for even stricter noise limits which can be monitored over time. We are missing an opportunity."

Castle Donington Councillor Gerald Dalby said the extended runway would only encourage more long-haul night flights of mainly older freight aircraft, meaning even more noise.

He said: "More stringent conditions need to be imposed by the council."

Council officers told the committee that there were no planning grounds for blocking for the development as it complied with government guidelines.

Committee chairman, Councillor David Stevenson, said: "We've never been able to impose any noise restrictions before now.

"I think this is a big step forward."

An airport spokesman said: "We are pleased that after nine years we now have permission to extend the runway. We will be considering the council's comments carefully."

Official figures show 2,632 complaints were made about disturbance from aircraft engines around the airport between April 2008 and the end of March 2009.

Over the years the airport has spent £1.5m insulating 502 nearby homes to keep out jet noise.

A consultation on the airport's draft noise action plan, a document it must produce to show how it is going to manage noise and reduce it where necessary in the coming years, ended on October 21.

Pledges from the airport include insisting airlines and freight operators use quieter aircraft, and giving financial support to people in the area who may need measures like new, soundproofed windows.