The survey by the Graduate Institute of International Studies here said up to 27 organizations, some which are connected to Al-Qaeda, possess the missiles, known as man portable air defense systems (MANPADS).
The shoulder-fired devices, which include Soviet-built SAM7s and US Stinger missiles widely distributed among anti-Soviet Mujahadeen in Afghanistan in the 1980s, are small enough to pack into the trunk of an automobile and are widely available on the black market.
"The threat to civilian airliners has the potential to affect the citizens of all states traveling on major air routes," said the survey.
The missiles came to the world's attention with an attempt to shoot down an Israel airliner shortly after takeoff from Mombasa two years ago. In November 2003, a cargo plane was hit by a missile shortly after taking off from Baghdad airport and had to make an emergency landing.
Among the 100,000 anti-aircraft weapons believed to be in circulation "is an unknown quantity of systems in the hands of non-state groups, some of which have been identified as terrorist organizations," the survey said.
"To date, at least 13 such groups are known to possess MANPADS with a further 14 groups reported to possess them. Of particular concern are those thought to be in the hands of groups loosely described as under the umbrella organization of Al-Qaeda."
The use of the missiles requires training, but "the disbanding of the Iraqi army has undoubtedly meant a number of soldiers trained in the use of MANPADS are now unemployed and seeking an alternative career," the survey said.
To combat the threat, the Israeli carrier El Al envisages equipping its aircraft with missile detection systems and decoys at a price of one million dollars (820,000 euros) for each plane, and the United States also is considering such a move, the survey said.
But it added that the latest missiles were more effective in getting past the defenses, and that only effective international controls on the weapons would reduce the threat.
The survey also said the more than seven million small weapons circulating in Iraq since the US-led coalition dismantled the Iraqi army could pose a threat to stability in the greater Middle East for years to come.
About 4.2 million firearms previously in the hands of the Iraqi armed forces, paramilitary troops or reserve forces have been stolen or sold on the black market, according to the report. Added to the 3.2 million firearms already owned by Iraqi civilians, this makes a total circulation of some 30 firearms for every 100 residents in Iraq, according to the survey.