Moody's affirmed CME Group Inc.'s Aa3 long-term ratings with a stable outlook following the announcement that the company plans to acquire NEX Group PLC.

"NEX is a good strategic fit for CME," said Moody's Senior Vice President Donald Robertson, adding that "combining CME's derivatives exchange and clearing activities with NEX's electronic trading platforms in the spot fixed income and foreign exchange markets would diversify CME's income into adjacent markets."

The outlook reflects the agency's expectation that the company would "prioritize debt reduction over its annual variable dividend."