FACTBOX: Treaty on Conventional Forces in Europe

(Reuters) - President Vladimir Putin has suspended Russia's participation in a pact limiting conventional forces in Europe, the Kremlin said in a statement on Saturday.

Here are some key facts about the treaty.

* The CFE pact limits the number of battle tanks, heavy artillery, combat aircraft and attack helicopters deployed and stored between the Atlantic and Russia's Ural mountains.

* The original CFE Treaty was negotiated among the then-22 member states of NATO and the Warsaw Pact. At the time the treaty was signed in November 1990, a goal was to replace military confrontation with a new pattern of security relations. It also was to establish a secure and stable balance of conventional armed forces in Europe at lower levels than before.

* The treaty came into force in 1992 and it has secured the reduction or destruction of about 60,000 pieces of equipment of types limited by the treaty since then.

* It was complemented by "The Concluding Act of the Negotiation on Personnel Strength of Conventional Armed Forces in Europe" (CFE 1a) in July 1992. This agreement resulted in the substantial reduction of armed forces and since 2001, over 700,000 troops have been withdrawn. There are now fewer than 3 million troops in the area of application, with an authorized ceiling of more than 5.7 million.

* It became and remains the cornerstone of security and stability in Europe, both in terms of the reduction of tensions relating to accumulated weapons through arms control at the regional level, and of greater stability through confidence building, transparency and information exchange.

* It was updated in November 1999 in Istanbul with leaders of 30 nations setting limits on conventional forces on a national basis instead of the bloc-to-bloc totals set in the 1990 document.

* The revised treaty, which gave sovereign states the sole right to consent to foreign forces on their soil up to set territorial limits, made it easier for NATO to enlarge into eastern Europe.

* The updated treaty will come into force after ratification by all 30 signatory nations. Only Belarus, Kazakhstan, Russia and Ukraine have ratified the revamped pact so far.

* Russia has been anxious for the treaty to be ratified so that the ex-Soviet Baltic states can sign up. Some Russian officials fear they could become NATO outposts for nuclear arms or army bases.

(Sources: Reuters; U.S. State Department (www.state.gov)