UPDATE 1-ACS seeks to present binding bid for Atlantia's unit in reasonable time

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MILAN, April 16 (Reuters) - ACS intends to present a binding bid for Atlantia’s motorway unit within a reasonable time frame, the Spanish company wrote in its second letter to the Italian group, two sources said on Friday.

In its communication the Spanish group headed by businessman Florentino Perez said it aimed at starting due diligence for Autostrade with the support of Societe Generale, the sources added. It did not specify exactly how quickly it would proceed with any bid for a business it values at 9-10 billion euros ($10.8-$12 billion).

ACS, a partner of Atlantia in the management of Spanish toll-road operator Abertis, last week expressed interest in the 88% stake the Italian group owns in the Autostrade per l’Italia business. Its move risks complicating government-backed plans to reclaim the asset.

Rome is currently backing a binding offer prepared by a consortium of investors headed by Italian state lender CDP.

Talks with Atlantia, which is controlled by the Benetton family, and the CDP-led consortium are part of an effort to end a dispute triggered by the deadly collapse of a bridge run by Autostrade in 2018.

Two sources said that in this second message, the Spanish company repeated it was interested in winning the support of the Italian government for a potential transaction.

The latest letter from ACS arrived on Friday as the board of Atlantia decided to call an ordinary shareholder meeting on May 28 to examine the bid submitted by CDP and its partners, Macquarie and Blackstone.

Atlantia said it would hold another board meeting next week to examine the CDP-led consortium bid “in order to ensure that all aspects of the background, the deal, the board’s own views on the fairness of the offer and any alternative scenarios are covered in the explanatory report” for shareholders.

“The board will thus have the opportunity to evaluate any changes to the offer that the CDP-led consortium might submit,” the infrastructure group said in a statement.

Some investors in Atlantia, including hedge fund TCI, have said that the offer from the consortium, which is based on a valuation of Autostrade equal to 9.1 billion euros, is too low.

The board of Atlantia will take a final decision on the matter only by May 28, it said. ($1 = 0.8349 euros) (Additional reporting by Clara-Laeila Laudette and Jesus Aguado in Madrid; Editing by Keith Weir)