(Updates with Atlantia statements on Italy unit stake sale and Abertis interest)
By Pamela Barbaglia and Stephen Jewkes
LONDON/MILAN, April 27 (Reuters) - Italy's Atlantia has agreed to sell 10 percent of its domestic motorway unit to a series of investors including Allianz for 1.48 billion euros ($1.6 billion) as it presses ahead with plans to bid for Spanish rival Abertis.
A tie-up between Abertis and Atlantia would create one of the biggest infrastructure groups in Europe, generating around 60 percent of its core profit outside Italy.
Rome-based Atlantia, which is 30 percent controlled by the Benetton family, has for some time been looking for ways to beef up its foreign business and diversify away from Italy. In a statement on Thursday Atlantia confirmed its interest in its Spanish rival and said it would consider a bid on condition the deal was friendly and created shareholder value.
Earlier on Thursday, sources said Atlantia had tapped banks to finance an upcoming cash-and-share bid for Abertis.
Atlantia's advisers Credit Suisse and Mediobanca and Abertis' adviser Citi have committed to provide financing for the transaction with a formal bid expected to be announced as soon as next week, the sources said.
The pool of financing banks will also include Italian lenders UniCredit and Intesa Sanpaolo and France's BNP Paribas, the sources said.
The overall financing package is estimated to be worth more than 10 billion euros, two of the sources said, with one adding it could involve a consortium of about 10 banks.
Spain's Santander and France's Credit Agricole are also expected to take part in the financing, the sources said.
Spokesmen at Abertis, Mediobanca, UniCredit, Intesa, BNP Paribas, Credit Suisse and Santander declined to comment while Atlantia, Citi and Credit Agricole were not immediately available.
Atlantia, which operates Rome's two airports and around 5,000 km of toll motorways, has long been trying to lure its Spanish rival to the negotiating table, sources said.
But Barcelona-based Abertis, a crown jewel of Catalonia, has only recently started contemplating the possibility of a sale to enable the business to cope with domestic challenges including a series of concessions that will soon expire, the sources said.
By 2021 Abertis will lose up to 1,000 km of toll roads in Spain, which run along the Mediterranean coast and around Seville, representing around 10 percent of the group's business.
Earlier this month Atlantia CEO Giovanni Castellucci said he did not see a need to sell any of Abertis's assets to fund a tie-up between the two.
But sources said the Italian toll-road operator would use the proceeds from the sale of the stake in its Autostrade per l'Italia (ASPI) unit to finance the deal.
Atlantia said on Thursday it had agreed to sell 5 percent of ASPI to a consortium 74 percent-led by Allianz Capital Partners and also including EDF Invest and DIF Infrastructure IV.
The consortium has an option to buy a further 2.5 percent by end October, it said.
A further 5 percent of ASPI was sold to China's Silk Road Fund.
Atlantia, which said the sale generated a gain of 736 million euros, was advised by Goldman Sachs, JPMorgan, Credit Suisse and Morgan Stanley, while legal advice was provided by Bonelli Erede.
Allianz, EDF and DIF were advised by Rothschild and Cleary Gottlieb. ($1 = 0.9189 euros) (Additional reporting by Francesca Landini in Milan, Stefano Bernabei in Rome and Robert Hetz and Andres Gonzalez in Madrid; Editing by Rachel Armstrong, Elaine Hardcastle and David Evans)