The British Army may rent helicopters from other countries or commercial companies to make up for a shortfall in Afghanistan and Iraq, Defence Secretary Des Browne last night hosted a summit of senior military personnel and civil servants to consider the options for securing more helicopter capability, though officials suggested a final decision may be some time off.

Potential sources for leased choppers include former Warsaw Pact countries, oil companies involved in offshore production or US security contractor Blackwater.

Nato is understood to be negotiating with Blackwater, which came under fierce criticism from the Iraqi Government and US Congress after an incident in which 17 civilians were shot dead in Baghdad.

Ministry of Defence officials said there would be no immediate outcome from the meeting though ministers and officials are acutely aware of the problem with sourcing helicopters.

Many of Britain's 114 deaths in Afghanistan have been caused by roadside bombs and suicide bombs directed at troops travelling by land. Analysts point out that when IRA roadside bombing in South Armagh in the 1980s forced the Army to move around in helicopters, 70 aircraft were supplied.

Helmand, which is six times the size of Northern Ireland, has just 16 passenger helicopters.

When the USSR occupied Afghanistan it had more than 1000 helicopters at its disposal.

British forces in Helmand can draw on Nato helicopters, including eight Chinooks capable of carrying up to 40 people, and four Royal Navy Sea Kings that can carry 10.

There are four Army Air Corps Lynx helicopters in Helmand but the heat affects their engines and they cannot fly between 11am and 11pm in summer.

There are also eight Apache helicopter gunships, which carry no passengers.

Commanders in Afghanistan have been offered more hours flying time each month from the Chinook and Apache fleets but the Secretary of State called last night's meeting in order to find some alternative solutions before the summer holidays.

As the meeting took place, 3 Commando Brigade, including Royal Marines from Arbroath, took part in final exercises before departing for Helmand.

They will raise the total of British forces in Afghanistan to more than 8000, the highest number in the country and almost twice the number deployed in Iraq.

Britain feels its Nato allies could contribute more aircraft but military sources have rejected suggestions that the number of fatalities in Afghanistan would have been lower if helicopter transport had been more readily available, pointing out that many operations require that troops travel by road.

The Ministry of Defence said its aim was to ensure a future helicopter fleet that has the right mix of numbers, capability and platform types, to support current operations and future requirements.

Extensive modifications have been carried out to improve helicopters in Afghanistan, including the fitting new rotor blades to Sea Kings to improve performance in hot, high altitude conditions.

The MoD plans to spend £6 billion over the next 10 years, to replace and enhance helicopter capability