UPDATE 1-Spanish court dismisses $4.3 bln claim by Abertis

(Adds details of case and ruling)

MADRID, Jan 29 (Reuters) - Spain's Supreme Court has dismissed a 4 billion-euro ($4.33 billion) claim filed by toll-road operator Abertis against the Spanish government over a highway concession, the court said on Monday, causing a sharp drop in shares of Abertis owners.

Shares of ACS and Hochtief, were down 7.9% and 8.7% respectively following the news, with Jefferies analysts saying some in the market had been expecting an award of at least 1 billion euros from the court. ACS has a 50% total stake in Abertis and Hochtief 20%.

The case relates to lane widening works carried out by Abertis since 2006 at the AP-7 motorway concession under an agreement with the Spanish government.

In early 2022, the government agreed to compensate Abertis for the works carried out to the tune of almost 1.1 billion euros, but Abertis, through its unit ACESA, challenged the decision in court, demanding 5.37 billion euros and arguing that the initial agreement included a traffic guarantee.

The Supreme Court said it did not accept Abertis' interpretation, explaining that the deal did not include a transfer of the risk of demand, but only provided for compensation for the investments and works carried out.

"In conclusion, the Supreme Court upheld ACESA's claim for investments amounting to 32.9 million...and dismissed the appeal in all other respects," the court said.

($1 = 0.9242 euros) (Reporting by Inti Landauro and Emma Pinedo, editing by Andrei Khalip)