Christoph Mueller, chief executive, blamed the losses on a cabin crew dispute at the start of the year.
He said the airline experienced a strong second quarter, recording a profit of 25.9 million euros (£22.9m).
“This result was underpinned by the continuing positive impact of our capacity management strategy, stabilised passenger numbers, strong yield growth and the absence of airspace closures in northern Europe which occurred in 2010,” he said.
“Although economic conditions in Ireland remain challenging, we are pleased with the booking profile for the rest of the year.
“We are also positive about our trading prospects for the remainder of 2011.”
Aer Lingus said that passengers numbers were up 8.3 per cent to the end of June, with an 8.4 per cent rise in yield per passen- ger.
Mr Mueller added: “We expect revenue growth in the second half to be broadly similar to that of the first six months.
“As a result, we are more positive about the profitability of the business in 2011 than we were at the start of the year.”
Aer Lingus was hit by industrial action involving cabin crew earlier this year, causing the airline to cancel a number of flights or make alternative arrangements for passengers.
Shares in the airline improved 7 per cent on the Dublin market yesterday.