"Students have the freedom to take any language of their choice as a first language, second or third language. If the student chooses Bengali, Hindi, English, Urdu, Gurmukhi, Nepali, as first language, he/she may opt for two other languages of their choice," Ms Banerjee said in a Facebook post.
"One of the three languages would have to be Bengali. The two other choices are completely dependent on what the students chooses," she said.
She said this method would enable them to reach regional, national and international standards.
"Bengal respects all languages and languages of all states. Our three-language formula shows how we really do... India is a vast country and the strength of our nation is unity in diversity.
"We must respect every mother tongue and also give every regional language its importance. We believe in the freedom of choice and the three-language formula," the West Bengal Chief Minister said.
Ms Banerjee's statement comes a day after state Education Minister Partha Chatterjee announced that from now, it will be compulsory for students to learn Bengali in schools from classes first to tenth.
The minister said even English medium schools affiliated to boards other than the West Bengal Board of Secondary Education will have to make provisions for teaching Bengali as a second or third language.