Last week, the LSE rebuffed a proposed $39 billion takeover bid from rival Hong Kong Exchanges and Clearing, which vowed to press on with its proposal by speaking directly to the London bourse's shareholders.
Thomson Reuters, a professional information company that is the parent of Reuters News, holds a 45% stake in Refinitiv.
Schwimmer said two big drivers of change going forward are the increasing importance of data and multi-asset class investment strategies.
"We think that the Refinitiv transaction is a very strong fit strategically from that perspective, and really positions the London Stock Exchange Group very well to take advantage of growth in these areas," Schwimmer told a conference held by derivatives industry body ISDA.
"I don't think there is a lot of controversy around the increasing importance and focus on data."
Refinitiv brings content and distribution on a global basis that would be transformational for the LSE, raising recurring revenues and lowering exposure to volatile market transaction volumes, Schwimmer said.
"It's a transaction that we feel very good about," said Schwimmer, a 20-year veteran of Goldman Sachs bank who became CEO of the LSE last August.
(Reporting by Huw Jones, editing by Deepa Babington and Jon Boyle)
