Brazil's Embraer signed an agreement on Tuesday to sell as many as 20 executive jets to China Minsheng Banking Co., marking what may be the first deal for planes from its factory in China.

Embraer expects the agreement to be converted into a firm order in the next five years and deliveries could start this year, it said in a statement.

The company did not specify whether the orders were for the Legacy 600 and Legacy 650 models, which are to be produced in China in a venture with local planemaker AVIC. Embraer reached a deal in April to start assembly in China, giving the world's biggest maker of regional aircraft a lifeline in a massive market where its future was in doubt.

"Both companies are confident that the complete line of Embraer's latest-generation products will meet the demands of the Chinese market, which is the focus of this deal," Ernest Edwards, Embraer's senior vice president for executive aviation, said in a statement.

Embraer's backlog of firm orders rose to US$16 billion at the end of the first quarter, although sales in China showed little improvement in the period, drawing concerns from some analysts.

In a June interview, Embraer Chief Executive Frederico Curado told Reuters that the company's sales team was already offering clients Legacy jets to be manufactured in China.

Curado said production at its China factory still depended on final approval expected in coming months.

"We are working with our partners to prepare worker training and machinery. It's advancing well," Curado said in the interview.

Voting shares of the company lost 2.5 percent on Tuesday to 10.97 reais in Sao Paulo. The stock has shed about 6 percent this year, compared with a 14 percent drop in the country's benchmark Bovespa index markets.