United Airlines Monday announced an order for 30 Embraer 175 jetliners as it updates its fleet of regional aircraft.
The US carrier did not disclose the price of the purchase.
The planes, built by Brazil's leading aircraft maker, will be added to the fleet of United Express. Flights are operated by partner carriers under the United Express brand.
The Embraer 175 jet will be the first 76-seat regional jet aircraft in the United Express fleet and consume 10 percent less fuel per seat than the current fleet of 50-seat aircraft, United said in a statement.
"With a large first-class cabin, wider fuselage, and larger overhead bins, this aircraft brings an improved regional flying experience to our customers," said Jim Compton, United's vice chairman and chief revenue officer.
United said it expected to take delivery of the aircraft in 2014 and 2015.
Embraer, in a separate statement, said that it had signed a firm order with United Airlines for the sale of the 30 175 jets, with options for an additional 40 of the same model.
If all options are exercised, the combined order for 70 aircraft has an estimated value of $2.9 billion at current list prices, it said.
In another statement, the company said it had earned a net profit of 61.7 million reais ($30.8 million at current rates) in the first quarter of 2013, a 67 percent drop from the same period a year earlier.
The world's third largest commercial aircraft maker blamed the sharp decline on higher taxes and employer obligations, coupled with a lower operating income.
In the first quarter of 2012, Embraer reported profits of 186.7 million reais, and in the fourth quarter, 253.7 million reais.
The planemaker delivered 17 commercial aircraft between January and March this year, four fewer than the same period of 2012, and 12 executive planes, one less than in the same period last year.