By Anna Peverieri

(Reuters) -France's Alstom is in talks about supplying high-speed double-decker trains for use through the Channel Tunnel, but no contract has been signed yet, the train maker said on Wednesday.

Contacted by Reuters, a company spokesperson confirmed the talks but did not name any of the operators involved, citing the confidential nature of the discussions, and said it would not disclose the potential size of any contract until officially signed.

The talks were first reported by the Financial Times, which said the world's second-largest train maker was discussing supplying trains on routes between London and continental Europe, such as Paris, Brussels and Amsterdam.

Speaking to analysts on a post-earnings call, Alstom's CEO Henri Poupart-Lafarge said deregulation in Europe's high-speed rail market was creating opportunities, as both new entrants and traditional operators seek to expand their fleets.

"Even traditional operators are now interested in acquiring more rolling stock to cope with this increasing demand," Poupart-Lafarge said. "We have made considerable progress to certify and homologate our trains to go in the tunnel."

He noted that Alstom's Avelia Horizon was the only double-decker high-speed train currently available on the market, offering low cost per seat and high capacity.

The spokesperson said the model met all technical requirements to operate in France, Britain and the tunnel between them.

Confirmed orders for the Avelia Horizon so far include 115 trains for France's SNCF, 12 for Proxima, the first independent company to enter the high-speed market in France, and 18 for Morocco's state-owned operator ONCF.

Alstom has been positioning the model as a key product for Europe's growing cross-border rail market, which has seen a rise in passenger demand amid a broader push for more sustainable travel alternatives.

(Reporting by Anna Peverieri in Gdansk, editing by Milla Nissi-Prussak)