Regulators are seeking a meeting.

Regulators in Europe are reportedly worried that the proposed merger of Essilor and Luxottica would concentrate too much market power in the hands of the combined entity.

Reuters cites an unnamed source saying that European Union regulators want to have a meeting with the two vision giants in coming days.

It's likely that the regulators are seeking "concessions to address their concerns," according to Reuters. If the European Commission isn't satisfied by what the companies offer, the next step could be a more detailed look at the merger.

In New Zealand, the Commerce Commission recently granted clearance for Essilor and Luxottica to merge their business activities in that country.

Luxottica, based in Milan, Italy, is the largest eyewear firm in the world, with a brand portfolio that includes names such as Ray-Ban and Oakley. Its retail division includes many well-known names, including LensCrafters, Sunglasses Hut and Pearle Vision.

Essilor, which makes lenses as well as instruments and equipment, is based in France. Its brand portfolio includes names such as Varilux, Crizal, Transitions and Foster Grant.

Read more at Reuters