The G4 segment includes GrandVision's four largest business units: (i) the Netherlands and Belgium; (ii) France, Luxembourg and Monaco; (iii) Germany and Austria; and (iv) the United Kingdom, Ireland including franchises in several Middle Eastern countries.
The G4 business units manage retail banners with own and franchise stores across these countries. Within the segment, GrandVision has market leading positions in Austria, Belgium and the Netherlands, and number 2 or 3 positions in France, Germany and the United Kingdom.
As of the end of 2018, the G4 segment operated a network of 3,387 stores, an increase from 3,348 stores in 2017. Key banners in the G4 segment include Apollo Optik in Germany with 856 stores, Pearle in Austria, Belgium and the Netherlands with 682 stores, Générale d'Optique in France with 624 stores and Vision Express in the UK, Ireland and Middle East with 620 stores.
In the G4 segment, revenue increased by 7.9% at constant exchange rates to €2,131 million in FY18 (2017: €1,981 million). Organic growth contributed 3.0% and acquisitions, particularly Tesco Opticians in the UK, which was acquired at the end of 2017, contributed 4.8%.
The total number of stores in the G4 segment increased by 39 to 3,387 (FY17: 3,348), mainly driven by store openings across the region.
Comparable growth for the segment was 2.4%, driven by
the strong performance in both Germany and France. In France, we achieved almost 2.5% comparable growth for the year, driven by the recovery of the industry and continued market share gains. Our German business achieved more than 5% comparable growth and high single digit revenue growth, also supported by store openings and small acquisitions.
In the Benelux segment achieved slightly positive comparable growth during 2018, as Belgium more than compensated for the lower comparable growth in the Netherlands.
In the UK, the weaker economic environment, driven by uncertainties surrounding Brexit, has put additional pressure on customers which we have largely been able to mitigate through growing e-commerce sales. Overall, we saw moderate growth as digital sales compensated for lower retail sales.
Adjusted EBITDA in the G4 segment decreased by 1.5% at constant exchange rates to €411 million (FY17: €418 million) as by integration and rebranding costs from Tesco Opticians acquisition and transformational investments in digital capabilities in the Benelux more than offset stronger EBITDA growth in Germany and France.
The adjusted EBITDA margin decreased by 181 bps to 19.3% in 2018 (FY17: 21.1%).