Mellon Financial

(MEL)

agreed to acquire

Chase Manhattan's

(CMB)

50% stake in ChaseMellon Shareholder Services, a joint venture run by the two firms.

Terms of the transaction weren't disclosed, but Mellon Financial said the purchase will be completed in the fourth quarter, pending regulatory approval.

Chase Manhattan recently agreed to acquire commercial and investment bank

J.P. Morgan

(JPM) - Get Report

.