The company quoted official statistics from Spain's airport authority AENA showing that Ryanair in July transported 2.98 million passengers to or from Spain, compared to 2.77 million for Iberia.

The budget carrier congratulated itself for having "dethroned Iberia as the preferred company in Spain."

The company, which began operating Wednesday from Barcelona's main airport El Prat, said in a statement it planned to add 12 new destinations from Madrid's Barajas airport this year, to reach a total of 44.

Iberia by contrast has said it plans to further cut its domestic offers in order to concentrate on international routes, in particular to Latin America.

Iberia is to merge with British Airways this year to create Europe's second-biggest airline by market value and compete more effectively in the fast-consolidating aviation sector.