Collocations for contributor - noun

important, key, significant, valuable
big, large
leading, main, major, principal
frequent, regular
The core of regular contributors is essential to the magazine.

occasional
long-time (AmE)
She was a long-time contributor to Time Magazine.

generous, wealthy
net
net contributors to the economy

campaign (AmE)
Politicians are often suspected of trying to appease campaign contributors from the oil industry.

corporate (esp. AmE)

contributor to
Carbon dioxide is the largest contributor to the greenhouse effect.