The dealership, run by José Baptista and his children, will operate the stand on a shift basis split among the team week by week.
The gallery, which retains Lisbon as its base, exhibits at the LAPADA Art & Antiques Fair in September and plans to open in Grays in October or early November.
Pedro Baptista said: “My father José has been going to London on business since the 1970s and Grays has always been a significant trade centre for him. As we do two or three antique fairs every year in London we have decided to have a base in Grays, which will help us to organise things and also to expand our contact with the trade, gain more experience and meet new clients.
“London is one of the most important trade centres in the world, and Grays, in the antiques world context, represents an important part of what is happening.”