LISBON—The Portuguese government has received three offers for national carrier TAP Air Portugal, including from the founder of Brazil's third-biggest airline and a consortium headed by Portuguese businessman Miguel Pais do Amaral.

With the offers in hand, the government hopes it will finally be able to privatize the loss-making airline it says is in dire need for a capital injection. Portugal tried to sell TAP in 2012, but it shelved the plan after the only prospective buyer—Latin American tycoon German Efromovich, owner of AviancaTaca Holding SA—didn't meet financial conditions set for a deal.

The Portuguese government is now offering up to 66% of the company—61% to investors and the rest to its employees.

Secretary of Transport Sergio Monteiro, who refused to give the name of the bidders or details of the offers, said the government will now evaluate them.

In 2012, Mr. Efromovich, through Aviaca's controlling company Synergy Group Corp., offered €35 million ($40 million) for 95% of the airline, plus a capital injection of €316 million and the assumption of about €1.1 billion in debt held by TAP.

Mr. Pais do Amaral last year told a Portuguese newspaper he would consider an initial public offering of the airline in the next few years if he bought TAP.

Brazilian-American businessman David Neeleman, the founder of Brazil's Azul as well as the U.S.'s JetBlue, told The Wall Street Journal in an interview that he bid on TAP. If he buys the carrier, it will be kept separate from Azul for legal reasons. His offer was made through a personal business holding called DGN, which has backing from some of Azul's investors and investment funds.

"I feel we have made a very good offer," Mr. Neeleman said, adding he is willing to invest heavily in TAP. He declined to say how much he offered.

Azul flies to more than 100 destinations, including in Brazil and the U.S. TAP operates flights to 82 destinations. Its extensive routes linking Europe to Brazil make it an attractive property particularly for Azul.

Nonetheless, they face risks buying TAP.

The company, which includes the airline and a maintenance unit in Brazil, reported a €85.1 million loss for 2014, higher than the €5.9 million loss in the previous year. Strikes and leasing costs hurt operations. It reported €1.06 billion in debt.

This month, the company faced a 10-day strike from pilots who have balked at terms of the privatization. For instance, they want more than 5% of the company to be set aside for workers. While many pilots didn't join the movement, the airline still lost about €35 million. The pilot's union said more strikes could take place.

The sale has also faced opposition from politicians and opinion-makers in Portugal who say TAP is a strategic company that should remain state-owned.

Antonio Costa, leader of the main opposition Socialist Party, recently said the state should retain the majority capital in the company. Portuguese general elections are scheduled for later this year, and the Socialists are heading some opinion polls against the ruling coalition.

Write to Patricia Kowsmann at patricia.kowsmann@wsj.com and Luciana Magalhaes at Luciana.Magalhaes@dowjones.com

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