Complex sentence: The building has since its inception housed the global headquarters of the Mellon Financial Corporation, after the merger between Mellon Financial and Bank of New York the building is now home to extensive operations run by the new company The Bank of New York Mellon Corporation.
Split into simpler sentences: The building has since its inception housed the global headquarters of the Mellon Financial Corporation. After the merger between Mellon Financial and Bank of New York, the building is now home to extensive operations run by the new company The Bank of New York Mellon Corporation.