The deal would jump Gannett's television holdings from 23 stations to 43, The New York Times reported.
The deal was set up as a cash agreement that values Belo at $1.5 billion.
Industry analysts said television stations are stepping on the gas when it comes to mergers.
"The larger deals are getting done faster than most people expected," said Robin Flynn, a senior analyst with SNL Kagan.
"There is doubtless more to come," Flynn said.
After buying Belo, Gannett would become the third largest local television station owner in the country if measured by revenue.
CBS Corp. has the highest revenue from local television stations. It owns 29 of them.
News Corp., which also owns the Fox television network, owns 27 local stations and is No. 2 in terms of revenue.
Gannett will jump past rival Sinclair Broadcasting Group to the No. 3 position, the Times said.
The deal gives Gannet a local television station in 21 of the country's top 25 markets. It values Belo at $13.75 per share, a 28 percent premium above the company's closing share price on Wednesday.