Amid growing concerns that terrorists have their hands on thousands of surface-to-air missiles looted from Libyan armories, Israel plans to equip all its airliners with a new defense system developed by the El-Op company.

El-Op, an electronics subsidiary of major defense contractor Elbit Systems, claims its product, known as C-Music, is the first commercially available airborne protection system for airliners and helicopters.

"This system is being installed on all civilian airliners in Israel," said Mike Yanuv of El-Op. "I can't give you the timeframe, but we're at the very advanced stages of development."

C-Music is the acronym for Commercial-Multi Spectral Infrared Countermeasure against shoulder-fired missiles whose military designation is man-portable air defense systems, or Manpads.

El-Op's general manager, Adi Dar, says C-Music can detect incoming missiles and deflect them using laser technology, rather than destroying them.

It's been certified by civil aviation authorities around the world, he said.

"We see a huge market for this application," he said. "The market out there is huge.

"You can do the math yourself, but there are thousands of helicopters and hundreds of strategic aircraft."

The Israeli government gave El-Op a $79 million contract to develop a missile defense system for Israeli commercial aircraft as part of its Sky Shield air transport defense plan.

El-Op declined to put a price tag on the system, but the Israeli media has pegged it at $1.2 million a unit.

However, despite the global terrorist threat from Manpads, the civil aviation industry has for several years shown little inclination to acquire anti-missile systems.

Israel Aerospace Industries, flagship of the Jewish state's high-tech defense industry, developed a system known as Flight Guard some time ago, but U.S. and European civil aviation authorities have refused to certify it for safety reasons.

"Our system has all the required licensing," said El-Op's Yanuv.

U.S. and European companies have been seeking to develop an anti-missile defense system for airliners for years, with no commercial success even though there are around 6,700 commercial aircraft operating in the United States alone.

Israeli efforts were intensified after Nov. 28, 2002, when al-Qaida jihadists fired two Soviet-designed SA-7 Strela surface-to-air missiles at an Israeli Arkia Airlines Boeing 757 shortly after takeoff from Mombasa, Kenya, carrying some 250 holidaymakers back home. Both missiles missed.

The U.S. Rand Corp. estimated some time ago as many as 40 civilian airliners were shot down by Manpads between 1975 and 1992, causing as many as 760 deaths.

Many of these missiles, such as the French Mistral, the U.S. Stinger, the British Blowpipe, the Swiss Oerlikon and Russia's SA-7, SA-14, SA-16 and SA-18 -- this variant is twice as effective as the SA-7 -- are widely available and much sought after on the illegal arms market.

They're relatively inexpensive and easy to conceal and carry. SAMs can be around 3 feet long, weigh 11 to 40 pounds and are easy to fire.

The surge in the proliferation of deadly SAMs following Libya's civil war may spur new efforts to produce effective defense systems for airliners.

Figures for the number of missiles missing in Libya vary widely. But Gen. Mohammed Adia of the National Transitional Council forces said Oct. 2 Col. Moammar Gaddafi's ousted regime "bought about 20,000 SA-7 missiles, Soviet or Bulgarian-manufactured" in the 1980s and 90s.

"More than 14,000 of these were used, destroyed or are now out of commission. About 5,000 of the SA-7s are still missing," Adia said.

U.S. officials put the figure of missing Libyan missiles at closer to 20,000. Worldwide, as many as 150,000 SAMs are believed to be in circulation with non-state armed groups.

Many of the Libyan SAMs that are unaccounted for, particularly the older ones, are probable no longer usable. Those more than 15 years old are most likely non-operational now.

The batteries expire after a few years and after a decade the electronics are no longer reliable. After 15 years, the rocket motor fails to function.

But those that remain operational can be deadly even in the hands of inexperienced fighters, as small aircraft and helicopters are highly vulnerable to even old-tech missiles such as the SA-7.

During the 1979-89 Afghan war, mujahedin fighters fired some 500 Strelas and shot down 47 Soviet aircraft and helicopters, and damaged another 18.