Ryanair has asked the UK's Competition and Markets Authority (CMA) to reconsider a 2013 decision ordering it to sell down its 29% stake in Aer Lingus.
One of the reasons for the order to sell most of its stake was the fact that Ryanair's shareholding might be an obstacle to Aer Lingus merging or being acquired by another airline.
But Ryanair said the fact that British Airways owner IAG has secured the support of Aer Lingus's board for a €1.36 billion bid for Aer Lingus disproves this point.
"The findings have now been contradicted and disproven by events, which demonstrate conclusively that Ryanair's shareholding in Aer Lingus does not prevent Aer Lingus from merging with, being acquired by other airlines," Ryanair said.
The airline's submission has been posted on the CMA web site.
Ryanair asked the authority to consider if has been a "material change of circumstances" since its August 2013 decision.
Events "fatally undermine the lawfulness of the proposed divestment remedy," the airline added.
The CMA said that interested parties have until March 17 to respond to Ryanair's statement.
A spokesman for the UK competition authority said that such a request happens in long running cases like the Ryanair-Aer Lingus situation where a period of time might have passed since the original decision.
Ryanair has made a series of legal challenges to the CMA decision and is planning to appeal it to the UK's Supreme Court.
