Switzerland is set to host a meeting of experts in November tackling the thorny issue of private security companies operating in a legal no-man's-land.
Active in more than 100 countries, independent military contractors have an estimated annual turnover of $100 billion (SFr123 billion), which is expected to double by 2010.
The Swiss government, with the International Committee of the Red Cross (ICRC), has launched an initiative to establish a proper legal framework for one of the world's oldest professions.
"We've invited as many government experts as possible to the November meeting," said Christine Schraner, deputy head of the directorate of international law at the foreign ministry.
The meeting is aiming to examine national and international regulations overseeing mercenary activities, to clarify states' international obligations in terms of humanitarian and human rights law, and to encourage states to share information.
Since 2004 the government has been looking much closer at the role and status of the burgeoning number of rent-a-cop businesses – private military contractors – working in conflict zones.
In Iraq alone, there are some 20,000-25,000 mercenaries employed by DynCorp, CACI International, Titan and Global Risks.
The government was initially keen to investigate whether any of these companies were based in Switzerland, as allegations of violations of humanitarian law against them might pose a threat to Swiss neutrality.
According to a government report published in December 2005, three companies based in canton Basel Country are active in war or conflict zones; two have their headquarters in Switzerland, while the other is based abroad, with just an office in Switzerland.
A report commissioned by canton Basel Country found that 12 other companies have expressed a wish to work in dangerous regions in the future.
The report also warned that private military firms might be tempted to set up their headquarters on Swiss territory to benefit from the country's positive image, in particular its policy of neutrality.
Swiss authorities admit however that they "sometimes have to rely on the services of private military contractors" when working abroad in conflict zones. Recently Meteoric Tactical Solutions, a controversial South African firm, provided security for the Swiss liaison office in Baghdad.
One major concern is that the growing demand for the services of mercenaries is happening while companies operate in a legal no-man's-land.
United States soldiers in Iraq found guilty of torture have received prison sentences, while CACI and Titan mercenaries guilty of the same crimes have avoided charges.
"We have been looking closely at this subject both in Switzerland and at the international level," said Schraner.
A meeting was organised by the foreign ministry in January 2006 together with nine other countries concerned by the activities of mercenaries.
"We're not giving them our backing; we're saying they can no longer be ignored," said Claude Voillat, the ICRC's head of relations with the private sector.
"Everyone uses these specialists, from multinationals to non-governmental organisations as well as journalists," said Voillat.
"Our job is to ensure that there is proper regulation so that there is a clear distinction between professional private military contractors that respect humanitarian law and the others."
swissinfo, Ian Hamel
CACI International was founded in the US state of Virginia in 1962. The company employs about 10,000 people. Its shares are floated on the stock market and turnover was $3 billion last year.
A member of a private army earns three to ten times more than a regular soldier. Total turnover in the sector is estimated at $100 billion annually.
The Swiss authorities have organised several meetings with foreign experts and government representatives over the past 12 months.
A non-public experts meeting on private armies is scheduled to take place in Montreux on Lake Geneva in November.
An estimated two million Swiss mercenaries served in foreign armies between the 14th and 19th centuries.
Under Swiss law, mercenary duties were outlawed in 1927 (in addition to a ban according to the 1848 constitution), except for members of the Swiss Papal Guards.
About 800 Swiss citizens fought for the Republicans during the Spanish Civil War.
An estimated 40,000 Swiss have also served in the French Foreign Legion since 1831.