CBS was attempting to negotiate a deal that would have seen The Big Bang Theory continue for another two seasons, with Parsons set to earn almost $1m per episode.
Hit sitcom The Big Bang Theory is coming to an end after 12 years.
E4 airs The Big Bang Theory in the UK.
CBS network and producer Chuck Lorre confirmed the news in a joint statement which read: “We are forever grateful to our fans for their support of The Big Bang Theory during the past 12 seasons.