* Atlantia pays 1.06 bln euros for 15.49 pct of Getlink
* Italian group remains committed to buying Abertis - CEO
* Group sees synergies if Abertis deal goes through - exec
* Atlantia's core earnings rose 6 pct in 2017 (Adds Atlantia CEO quotes, details, Getlink CEO quote)
MILAN/PARIS, March 2 (Reuters) - Atlantia has bought a 15.5 percent stake in the operator of the Channel tunnel for more than 1 billion euros ($1.2 billion), it said on Friday, adding the deal did not change its plan to buy Spain's Abertis.
The Italian motorway and airport operator said it had become the largest single shareholder in France's Getlink, which runs the undersea link between Britain and France.
"This is a good financial investment, a good investment for the long-term but it is not an alternative to Abertis," Atlantia CEO Giovanni Castellucci told analysts on a conference call.
He said the group had enough financial room for both deals, should its plan to buy toll-road company Abertis go through.
Atlantia is competing with Hochtief, the German arm of Spanish builder ACS, to win control of Abertis.
The battle effectively pits the Benetton family, which controls Atlantia, against Spanish businessman and Real Madrid president Florentino Peres, the leading investor in ACS.
Hochtief is currently in the lead, with an offer valuing Abertis at around 16.5 billion euros, compared with the Italian company's bid of just over 15 billion euros.
"Any decision on Abertis will be taken after the approval by (Spanish market watchdog) CNMV of Hochtief's bid. Talking before is useless," Castellucci said.
Sources have told Reuters that Atlantia has secured financing to sweeten its offer, but it will only move in the final part of the acceptance period for the two offers.
It is up to the Spanish regulator to kick start the acceptance period and it has been reviewing Hochtief's offer for more than four months.
Atlantia, which also said its core earnings rose 6 percent on a like-for-like basis to 3.66 billion euros last year, gave little away about its plans, adding only that it had not considered potential synergies when calculating the offer announced for Abertis in May.
"If the deal with Abertis goes through there could be room to integrate assets in some countries where both groups are present, extracting potential synergies," Head of Corporate Finance Massimo Sonego told analysts.
Such synergies could justify sweetening the bid price.
Atlantia confirmed it would increase the dividend on its 2018 results by 40 percent compared with the 0.97 euros paid on 2016 results should it succeed in acquiring Abertis.
Following its investment in Getlink, the Italian firm said it expected to be offered a seat on the board.
"The arrival of Atlantia, a major player in the infrastructure world, is fantastic news, a sign of stability and very positive for our shareholders and our staff," Getlink CEO Jacques Gounon said in Paris.
($1 = 0.8123 euros) (Additional reporting by Dominique Vidalon in Paris Editing by Mark Potter)