The London Stock Exchange is acquiring the FSA's transaction reporting service for £15 million.
Subject to Office of Trading clearance, the LSE will incorporate the FSA's transaction reporting service (TRS) into its own web-hosted UnaVista approved reporting mechanism (ARM).
The LSE said existing FSA TRS clients "will benefit from UnaVista's significant functionality enhancements", as well as the opportunity to use the same user interface to access other systems on the UnaVista platform, including reconciliations and the multi asset class trade confirmation portal.
David Lester, director of information services at the LSE, said: "Customers will benefit from a significantly improved product. This underlines our commitment to our customers in assisting them with all their execution and trade processing needs."
Next year, the FSA will be replaced by the new Prudential Regulatory Authority (PRA) - part of the Bank of England - and the Financial Conduct Authority (FCA), a new government agency.
Despite being on the way out, the FSA has recently signed IT services deals with both Capgemini and Steria. The services provided will support the transition to the FSA's succesor bodies and their own IT needs.
This spring the LSE completed the migration of its technology to its new Millennium Exchange platform, which came after weeks of severe technical problems.