Portuguese flag carrier airline TAP posted a net loss of 46 million euros (about 50.4 million U.S. dollars) at the end of 2014, crippled by strikes and operational troubles in the second quarter, Portuguese Lusa News Agency revealed on Wednesday.

According to the airline, the late arrival of new airplanes, 22 days of strikes and some operational issues took a toll on the company to the tune of 108 million euros.

"We knew we would have a difficult year and that is what happened. Unfortunately, the results were not good," TAP President Fernando Pinto said at a press conference on Wednesday.

TAP posted a profit of 34 million euros in 2013, and the losses in 2014 interrupted a five-year cycle of positive financial results.

Portugal is trying to sell TAP, which unions have said would lead to job losses and lower wages. However, in January, the government revealed it was imposing a ban wherein future buyers of TAP could not lay off workers en masse after the unions threatened to strike over the Christmas holidays.

TAP's privatization is one of the terms set out in the 78-billion-euro bailout program Portugal signed in May 2011 with the troika of international lenders - the European Commission, the International Monetary Fund, and the European Central Bank.

Portugal re-launched the concession of TAP in November last year, after the first attempt was stalled at the end of 2012 because Brazilian investor German Efromovich, owner of Avianca airline brands in South America, didn't meet the necessary banking requirements on time.