UPDATE 1-ACS, Atlantia accord does not aim to break up Abertis assets- ACS

(Adds details, comments)

MADRID, March 15 (Reuters) - An agreement between ACS and Italy's Atlantia to make a joint 18-billion-euro ($22.2 billion) bid for Abertis does not include plans to break up the Spanish highway concessions company's assets, the ACS chairman said on Thursday.

Spanish builder ACS and Atlantia agreed to jointly bid for Abertis on Wednesday, ending a 5-month bidding battle for the Spanish toll-road operator and easing political concerns.

Spain's government has been worried that an Italian takeover would have left important highways under foreign ownership. However, the proposed joint bid will be made by ACS-controlled Hochtief, securing Spanish influence.

The new company that emerges from the joint bid will be Spanish, ACS Chairman Florentino Perez told a news conference in Madrid to explain the deal.

Some newspapers have speculated that Atlantia and ACS could choose to break up the Abertis business in the future, but Perez denied that was the intention.

"We've not reached this agreement to break up Abertis and share out its assets, full stop. This is a long-term project," Perez said.

Under the terms of the proposed deal Atlantia will own 50 percent plus one share in the entity which will ultimately own Abertis, plus an additional, indirect stake through a related purchase of around 25 percent in Hochtief.

The chairman of the resulting company will be appointed by ACS and its German affiliate Hochtief, while Atlantia will name its CEO, Perez said.

Hochtief CEO and chairman Marcelino Fernandez Verdes said his company had identified potential projects worldwide from the joint deal worth around 200 billion euros over the next four years. ($1 = 0.8093 euros) (Reporting by Jesus Aguado and Jose Elias Rodriguez; Writing by Paul Day; Editing by Adrian Croft)