The nation’s largest cable operator has announced it has agreed to buy Tribune Media, which owns the Tribune Media Network and The Chicago Tribune.

Comcast said the transaction will close by the end of March.

The deal will give Comcast a 35 percent stake in Tribune Media as well as its television, digital and online businesses.

The combined company will include more than 200 million subscribers and is expected to be valued at $45.6 billion.

The Tribune Company has been a pioneer in the online news business for more than a decade, with its flagship online site the Chicago Tribune, owned by Tribune Media’s parent company, Tribune Media Enterprises, and the Chicago Sun-Times, owned and operated by Tribune Enterprises.

The Chicago Sun Times is a subsidiary of Tribune Media.

The Chicago Tribune was the largest daily newspaper in the United States by circulation in 2016, with more than 5 million print subscribers, and had a market value of $3.8 billion.