For some reason I have a hard time believing the Russians on this denial:

Russia’s arms-export monopoly on Monday denied Israeli claims that it plans to deliver S-300 surface-to-air missiles to Iran or Syria, the Interfax news agency reported.

“We have no information of this kind,” a spokesman for the state-owned firm, Rosoboronexport, said when asked about potential sales of the sophisticated anti-aircraft weapons to Tehran or Damascus.

The denial came as outgoing Israeli Prime Minister Ehud Olmert was due to arrive in Russia for a two-day visit in which concerns over Iran are expected to top the Israeli agenda.

His defence minister, Ehud Barak, on Sunday urged Russia not to upset the strategic balance in the Middle East with arms sales to Muslim countries.

Israeli media say the Jewish state is concerned by the possible sale of S-300s to Tehran, which could use them to foil Israeli or US airstrikes against sites linked to Iran’s alleged nuclear weapons programme.  [Space War]

The Russian S-300 missile also known by the NATO designation of a SA-10 has a range of 150 kilometers and can destroy an aircraft at a maximum altitude of 30 kilometers.  It also has the ability to shoot down not only aircraft but ballistic missiles as well.  Its radar has the ability to simultaneously track 100 targets while being engage 12 of them at the same time.  The radars maximum range is that it can detect ballistic missiles out to 1000 kilometers and cruise missiles and aircraft up to 300 kilometers. 

This is a pretty impressive system which appears to be on paper anyway similar to a US PATRIOT  missile.  However, as just this past year during Operation Orchard, the Israelis defeated the Russian made air defense systems in Syria and I wouldn’t be surprised if they were able to do it again.