GDANSK (Reuters) -Poland's biggest e-commerce platform Allegro expects its earnings growth to slow down to 4-7% at home in the fourth quarter, it said on Thursday after its third-quarter core profit met market expectations.

Allegro's quarterly adjusted earnings before interest, taxes, depreciation and amortisation (EBITDA) rose 13.5% to 883 million zlotys ($214.63 million) in the Polish market, compared with 880 million zlotys expected by analysts in a company-compiled consensus.

Gross merchandise value (GMV), an industry metric used to measure transaction volumes, rose 10.8% on the year to 14.7 billion zlotys in Poland, its biggest market.

"Allegro's Polish shoppers have been increasing their spending with us at the fastest annualised rate in a year, despite signs of weakening retail sales," Chief Financial Officer Jon Eastick said in a statement.

The company cited the base effect of monetisation measures, additional spending on marketing, logistics services and team expansion as reasons for the expected earnings slowdown.

Still, it said its adjusted EBITDA to GMV margin should come above its medium-term target of 5.3-5.7% for the full year.

Allegro expects GMV growth at home to come in an 11-13% range in the October-December quarter, which includes the peak holiday shopping season.

It however sees an adjusted EBITDA loss for its international operations at 210-230 million zlotys, which would bring the consolidated figure to a decline of 2-6%.

Allegro, already a go-to shopping platform in Poland, bulked up in the region with the acquisition of Mall Group in 2022, subsequently launching its marketplace platforms in the Czech Republic, Slovakia and Hungary.

While the deal extended its footprint and gave it access to 32 million potential customers, its international operations have so far been a drag on Allegro's profitability as it transforms Mall legacy business and invests in new marketplaces.

Allegro said active buyers reached 2.8 million on its platforms in the Czech Republic and Slovakia, while GMV in those markets was up 8% quarter-on-quarter.

CEO Roy Perticucci said in the statement that Allegro was also readying launches in Slovenia and Croatia, which should arrive in the coming quarters.

($1 = 4.1140 zlotys)

(Reporting by Anna Pruchnicka; Editing by Himani Sarkar and Milla Nissi)