A green energy company which wants to erect seven giant wind turbines on the Northumberland coast will have to wait a little longer to find out whether planning approval will finally be confirmed.

Hainsford Energy was given permission in principle six months ago to improve its Blyth Harbour Wind Farm by replacing the nine turbines with seven much bigger and more powerful machines along the harbour wall and nearby Battleship Wharf.

Wansbeck councillors agreed to approve the scheme, for six 125m turbines and a seventh which would be the biggest land-based turbine in Europe, at 163m.

However, final planning permission was delayed after Newcastle Airport asked the Government to call the application in and order a public inquiry into fears the structures would interfere with air traffic control radar and cause safety and operational problems. Now, after consultation with the Civil Aviation Authority and legal and technical advice, Wansbeck planners have confirmed their original decision to approve the Hainsford Energy scheme.

It will now be referred back to the Government Office for the North East (Gone) for a final ruling on whether the application can be dealt with by the council or must be referred to the Secretary of State and a possible public inquiry.

A decision is expected in the next few weeks. Airport managers say the turbines' height means they would be likely to create "clutter" on radar screens and be confused with aircraft.

They also say they might have to create an exclusion zone around the wind farm and re-route flights by at least five nautical miles, increasing the airport's carbon footprint and noise over homes.

Wansbeck Council officials took further legal advice and independent guidance from aviation consultants before recommending councillors to confirm the decision taken last January. Yesterday senior planning and development control officer Richard Gee said the consultants and a barrister had concluded the original decision was sound and there was no need to change it.

He said they had advised that the airport had not demonstrated the seven turbines would have an adverse effect on the operational safety of the airport.

It is now up to Gone either to lift a direction barring the council from issuing final approval or refer the final decision to the Secretary of State.