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From a West Point study of jihadists in Iraq:

A breakout of the hometowns of Libyan jihadists who showed up in Iraq:

Note that the 84% of the jihadists came from Darnah and Benghazi, both rebel strongholds that were (as pointed out in the West Point study) previously the scene of Islamist uprisings in the mid-1990's.

From a West Point study of jihadists in Iraq

Another study counts few from Libya.

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Both studies contain small sample sizes, and do not conclusively represent the thousands if not tens of thousands of foreign fighters in Iraq.

Here's a third report.

The Guardian: The CSIS disputes reports that Saudis account for most of the foreign insurgents and says best estimates suggest Algerians are the largest group (20%), followed by Syrians (18%), Yemenis (17%), Sudanese (15%), Egyptians (13%), Saudis (12%) and those from other states (5%). British intelligence estimate the number of British jihadists at about 100.

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I don't see Libya listed.

Another study on foreign fighters in Iraq....

In July 2007, the Los Angeles Times reported that 45% of all foreign militants targeting U.S. troops and Iraqi civilians and security forces are from Saudi Arabia; 15% are from Syria and Lebanon; and 10% are from North Africa. 50% of all Saudi fighters in Iraq come as suicide bombers. In the last six months, such bombings have killed or injured 4,000 Iraqis.[36] According to a U.S. military press briefing on October 20, 2005, 312 foreign nationals from 27 different countries had been captured in Iraq from April to October 2005.[37] This represents a component of the Iraqi resistance movement, which also includes a nationalist movement encompassing over 30 Shia and Sunni militias. Foreign Insurgents captured in Iraq in the 7-month period April–October 2005:

Egypt - 78
Syria - 66
Sudan - 41
Saudi Arabia - 32 U.S. - 15
Iran - 13
Palestine - 12 Libya - 7
Turkey - 6
Lebanon - 3
India - 2
Quatar - 2
Others - 14

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