FACTBOX-Facts about Armenians in Iran

(Reuters) - Iran is applying for an ancient Armenian monastery, St Thaddeus Church, to be declared a U.N. World Heritage site. If successful, it would be the first such site in the Islamic Republic to be a Christian monument.

Here are some facts about Armenians in Iran:

* Armenians are Iran's largest Christian minority, but their numbers have declined since the 1979 Islamic revolution. Representatives of the minority say there may be as few as 100,000 Armenians left, representing less than 0.2 percent of the Islamic Republic's 70 million population.

* Christians, Jews and Zoroastrians, who are members of a creed that pre-dates Islam and Christianity, are recognised religious minorities in the Islamic state's constitution and free to perform their religious rites "within the limits of the law."

* In ancient times Armenians in the Persian empire shared religious and other ties with Persians -- the largest ethnic group in modern Iran -- but their conversion to Christianity and the 7th century Arab Muslim conquest of the empire changed that.

* Most Armenians in Iran today live in the capital Tehran and other cities, including Esfahan, and northwestern areas. They are known for being skilled in technical professions, for example as electricians and car mechanics.

* Armenians in Iran have the right to school education in their own language, which belongs to a separate branch of the Indo-European family of languages and has a unique 39-character script.

(Sources: Reuters, Iran's constitution)