In a statement, Norwegian said it has received two separate conditional proposals from IAG to buy 100 per cent of its share capital.
It said the bids were unanimously rejected on the basis that they undervalued the low-cost airline and its prospects.
IAG took a 4.6 per cent stake Norwegian last month.
Norwegian said its Board ‘remains fully committed to delivering on its stated strategy, for the benefit of all shareholders’.
The disclosure came as IAG, parent to British Airways, Iberia, Aer Lingus, Level and Vueling, raised its profit forecast on the back of its first quarter results.
Operating profit for the three months to March 31 rose from €160 million in the previous year to €280 million, with pre-tax profit up to €246 million.
Passenger numbers grew by 8.5 per cent to just under 23 million and capacity jumped by 4.1 per cent, pushing revenue up 2.1 per cent to just above €5 billion.
