The Spanish government is aiming to sell up to 49% of cash-strapped AENA, through a placement of up to 21% with institutional investors and selling the remainder through an initial public offering, according to Reuters.
Officials are reported by the media outlet as saying the aim of the sale is to make the company more efficient and attract more tourist flights, and the sale is expected to net about €2.2 billion ($2.97 billion), while the company's debt is about €11.5 billion.
AENA owns 46 airports in Spain and also has international interests, such as a stake in London's Luton Airport, but just 13 of them were profitable in 2013, including Madrid, Barcelona and tourist destinations such as Palma de Mallorca, Ibiza and Tenerife.
The gateway operator made a profit of €597 million in 2013, after huge cost reductions, including staff cuts and benefiting from airport tax increases, up from a €215 million loss in 2011.
AENA is the biggest airport operator in the world in terms of passengers, and handled more than 187.4 million travellers last year.