The deal, which will be included in Embraer's order book for the third quarter, is valued at $2.1 billion, the planemaker said in a securities filing.

The planes will be operated by United Airlines under the United Express brand, Embraer said, adding it comes on top of the company's deal with Republic in Jan. 2013, when it signed a firm order for 47 E-175 jets with 47 options.

(Reporting by Asher Levine; Editing by Bernadette Baum)

Stocks treated in this article : Republic Airways Holdings Inc., Embraer SA