Shares of Pilgrim's Pride at last check rose 20% to $27.23. The 52-week high on the stock is $26.28.
JBS already owns more than 80% of Pilgrim's Pride. In 2009 it had agreed to buy a majority stake in the Greeley, Colo., company.
Pilgrim's Pride produces about 16% of the country's chicken meat.
JBS’s holding in PPC enabled the parent “to expand its portfolio in the U.S. beyond beef and broaden its retail distribution network,” the Sao Paulo company said.
Buying the rest of the shares would simplify JBS’s corporate structure and give it more flexibility to grow and serve customers, it said.
Conditions to closing the deal include approval by a committee of independent directors on Pilgrim's Pride's board and a vote of holders of a majority of the shares.
Earlier this year, a U.S. federal grand jury indicted four former executives at Pilgrim's Pride for their roles in an alleged price-fixing conspiracy.
The company itself pleaded guilty in February and was ordered to pay a $107.9 million fine to settle price-fixing charges.
In its most recent quarter, Pilgrim's Pride reported earnings of 63 cents a share on revenue of $3.64 billion.