Indian-American mathematician Srinivasa S R Varadhan won the prestigious $850,000 Abel Prize for mathematics this year for his "fundamental contributions to probability theory," it was announced on Thursday.

The 67-year-old professor of New York University's Courant Institute of Mathematical Sciences would receive the honour, viewed as equivalent of a Nobel prize, "in particular for creating a unified theory of large deviation," the award committee said.

The 6 million kronor award was created by the Norway government in 2002 to mark the 200th birth anniversary of the great Norwegian mathematician Niels Henrik Abel.

"Varadhan's work has great conceptual strength and ageless beauty. His ideas have been hugely influential and will continue to stimulate further research for a long time," said the citation from The Norwegian Academy of Science and Letters, according to a release from the NYU.

He is expected to receive the Abel Prize from King Harald V of Norway in Oslo on May 22.

Professor Varadhan was born in Chennai and received his BSc honours degree and MA from Madras University. He did his PhD from the Indian Statistical Institute in Kolkata before coming to Courant as a post-doctoral fellow in 1963.

He has spent his entire professional life there, serving two terms as its director (1980-1984 and 1992-94).