* Salini at heart of plans to create Italian building giant
* Concern over shares in holding company pledged to Natixis
* Salini seeks progress on Astaldi deal by Aug. 1
By Stefano Bernabei and Stephen Jewkes
ROME/MILAN, July 30 (Reuters) - The role of French bank Natixis is presenting a hurdle to efforts by Salini Impregilo to create an Italian construction champion, two sources close to the matter said.
Salini, Italy's biggest building company, is looking to secure the backing of state lender Cassa Depositi e Prestiti (CDP) for its efforts to revive the country's moribund construction industry.
But CDP, expected to inject up to 250 million euros ($279 million) in the "Progetto Italia" plan, is concerned about shares in the family holding Salini Costruttori pledged to Natixis as collateral for a loan, the source said.
The source did not specify how many shares were involved in the Natixis margin loan deal but said the number could be significant. Salini Costruttori owns around 67% of the listed builder.
The source said CDP was worried about backing a project to create a national player that could be influenced by a French investor. Rome is keen to rescue an ailing sector that remains a major employer and driver for ambitious infrastructure plans.
In a letter sent to Salini dated July 15 and seen by Reuters, CDP said it was important that "ties currently existing on Salini shares held by Salini Costruttori be revised to the satisfaction of (CDP)", but gave no further details.
Salini, which has worked on projects ranging from expansion of the Panama Canal to a new subway line in Saudi Arabia, is launching a takeover bid for troubled rival Astaldi as a first step in a broader 1.6 billion euro ($1.8 billion) plan to consolidate the industry and create a business that can compete globally.
Corporate France has been the biggest overseas investor in Italian companies over the past decade with deals totaling $43.3 billion, Refinitiv data shows.
Some have been closely scrutinised by Rome, worried over the vulnerability of corporate champions such as Telecom Italia , in which CDP took a direct holding after Vivendi built a controlling stake.
Last month Fiat Chrysler abandoned its $35 billion merger offer for Renault, blaming French politics.
Salini, Natixis and CDP declined to comment.
Salini has said its offer for Astaldi is conditional on bagging funding commitments by Aug. 1 from CDP and banks.
Media reports have said the deadline could be pushed back to allow more time to find a solution on Natixis and iron out a few other outstanding issues such as governance.
"There are still some issues to be closed as is normal in such a complex and important deal," another source familiar with the talks said, adding discussions were ongoing.
Salini, whose long-standing CEO Pietro Salini has been a driving force behind the consolidation push, made no mention of its Project Italy plans in first half results released on Tuesday.
CDP, which is almost 83% state owned, has a board meeting scheduled for Thursday. ($1 = 0.8972 euros) (Additional reporting by Inti Landauro in Paris Editing by Keith Weir)