PORTLAND, Maine — Multinational meat giant Tyson Foods will seek to buy AdvancePierre, the company which includes the former Barber Foods plant in Portland, for $4.2 billion.

Tyson’s intent to buy Cincinnati-based AdvancePierre was announced in a press release Tuesday morning. The sale has received approval from the boards of both companies and, pending regulatory approval, is expected to close in the third quarter of 2017, according to the statement.

AdvancePierre operates a St. John Street plant, where it employees about 300 people making frozen, stuffed chickens, sandwiches and other prepared foods.

The plant was part of AdvancePierre’s 2011 acquisition of Barber Foods, a sale that resulted in more than half of the Portland-based company’s workforce being laid off. AdvancePierre invested millions of dollars into modernizing the equipment at the 150,000-square-foot Portland factory, ahead of its initial public offering in 2016.

As of last year, AdvancePierre was the 11th largest non-government employer in Portland, whereas Barber Foods was the fifth largest in 2007, according to a city bond filing.

Tyson’s planned purchase of AdvancePierre would result in a “consolidated manufacturing footprint,” according to the release, although it is unclear whether that would mean further changes at the Portland plant.

Barber Foods “has a strong heritage in both retail and foodservice channels and we look forward to building upon its foundation of quality,” the release states.