Blackwater Worldwide, the private security company whose guards are accused of shooting dead 17 Iraqi civilians last year, is attempting to reposition itself as a peacekeeping force as work in Iraq begins to dry up.

Adverts have appeared in security industry journals featuring mothers feeding babies and Blackwater guards smiling as children play in the street.

The US-based company has also set up a subsidiary, Greystone, which is seeking to win peacekeeping and security work from the UN, aid organisations and foreign companies. The improved situation in Iraq combined with a withdrawal of troops and less reconstruction spending means that there is less need for private security companies (PSCs).

Blackwater insists that it is business as usual. But, for everyone else, profits have collapsed and companies are looking for mergers or moving into new regions.

The crash has come after a short but very lucrative boom in Iraq. Blackwater is reported to have earned $1.5 billion from the US Department of Defence and the Foreign and Commonwealth Office has spent about £178 million on PSCs during the past five years. The boom was triggered by Donald Rumsfeld, the former US Defence Secretary, who decided to outsource semi-military work so that the US and UK could deploy smaller forces.

Tasks such as guarding bases, convoys and government officials were given to PSCs, and dozens of companies run by former military officers sprang up to fill the void. They hired other soldiers, sometimes at rates of $1,000 a day, but the new outfits operated under almost no supervision or chain of command.

Blackwater, set up by Eric Prince, a former US Navy Seal, remains under investigation for an incident in Nisoor Square, Baghdad, last September when guards protecting a convoy allegedly opened fire, killing 17 and injuring 24. In another incident, in 2004, four guards were ambushed in Fallujah and their mutilated bodies hung from a bridge, prompting a counter-attack on the city by US forces.

Symon Hill, spokesman for Campaign Against Arms Trade, said: “They are irresponsible, unaccountable and a danger to the reputation of anybody employing them.”

The idea of an outfit such as Blackwater moving into corporate and humanitarian work has been scoffed at by both competitors and campaigners. John Holmes, a retired major-general in the British Army and now a director of Erinys Security, said: “Blackwater is going to have a stigma about them now.”

Mr Hill added: “Private security firm is a worrying euphemism. It would be more honest to call them mercenaries.”

A spokeswoman for Blackwater said: “Blackwater's only role in Iraq is to provide defensive security, which we continue to do. We have always looked globally for opportunities to serve the US government and we continue to do so.”

The Iraq boom was lucrative while it lasted but for many former soldiers the private security business is no longer the path to riches that it once was.

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