Ryanair has vowed to fight the UK Court of Appeal's decision to uphold an earlier ruling that it must cut its stake in rival Irish airline Aer Lingus to just 5 per cent.
The budget carrier said it will now take its case to the UK Supreme Court as the decision "raised human rights issues of significant public importance".
The UK Competition Commission (now the CMA) in 2013 investigated Ryanair's 29.8 per cent shareholding in Aer Lingus to see if it prevented that carrier from merging to remain competitive (see news, August 2013).
It concluded Ryanair's shareholding could "substantially lessen" competition on routes between Ireland and the UK, and told it to slash its stake to 5 per cent.
Ryanair appealed the findings, but the UK Court of Appeal this week upheld the decision.
The airline said it will now take its case to the UK Supreme Court.
Ryanair chief marketing officer Robin Kiely said: "While we note the Court of Appeal's ruling on the CMA's Final Report on Ryanair's 29 per cent stake in Aer Lingus, this judgement ignores the fact that the CMA's Final Report was based on fanciful hypotheses, secretive 'evidence' and unsubstantiated assumptions.
"As such, we have instructed our lawyers to appeal this ruling to the UK Supreme Court.
"Additionally, Ryanair has now requested a formal review by the CMA of its Final Report, and a withdrawal of the divestment remedy, in light of the recent IAG offers for Aer Lingus, which wholly disprove the CMA's unsubstantiated claim that Ryanair's shareholding somehow prevented other airlines from merging with or bidding for Aer Lingus.
"Clearly the CMA's case has now been totally undermined by the IAG offers."