The BBC called Einojuhani Rautavaara "one of the most notable Finnish composers after Jean Sibelius".
Rautavaara, 87, who died on Wednesday night in Helsinki from complications following an operation, was known for major works including Cantus Articus and Symphony No.7 "Angel of Light".
Rautavaara's wide-ranging repertoire included operas, symphonies, orchestral works, chamber music and choral works.
During his career, Rautavaara was also a teacher and professor at the Sibelius Academy.
As a young man, Rautavaara won a scholarship to study music at Juilliard in New York City. In 1954, he received international attention for the first time when he won the Thor Johnson Contest for his composition "A Requiem in Our Time".