The Champions League last-16 tie at the Bernabeu will be covered live by 40 television channels and 16 radio stations.
Real's Champions League showdown with United will be covered by 500 communications media representatives from all corners of the globe.
Four hundred print journalists and 105 photographers, the maximum capacity that the stadium can accommodate, with a total of 220 communications media from most of Europe, Africa, the US, the UAE, Japan, China, Mexico, Argentina, Brazil, India and Israel.
Kevin Alavy, managing director of Sport+Entertainment, an agency specialising in sport sponsorship, is expecting a global audience of about 200million.
"It may well be that this is the most watched last-16 match in the history of the Champions League," he told the Telegraph.