Fiat Chrysler and CIR Holding announced Wednesday they were merging their editorial groups, bringing top Italian dailies La Repubblica and La Stampa under one roof.

The deal would create "a leading European group in the daily and digital information industry," CIR said in a statement, adding that the merger would be complete by June 30 and the dailies would keep their titles.

The most significant consolidation in Italy's struggling print media sector since digitalisation unites the production of country's third and fourth-best selling papers.

La Repubblica, founded in 1976, has a left-leaning perspective while La Stampa, first published in 1867 in industrial Turin in Italy's north-west, is considered the voice of the billionaire Agnelli family, founders of the Fiat car maker.

L'Espresso, publisher of Rome-based La Repubblica, and Itedi, which owns the Turin-based La Stampa, realised a combined turnover of about 750 million euros in 2015, CIR said.

Fiat Chrysler controls 77 percent of Itedi, while CIR is the parent company of L'Espresso. Rumours of the impending merger boosted shares of L'Espresso on Wednesday, which closed up 15.09 percent on the Milan stock exchange.