I found this interesting art pottery vase in a local shop at a reasonable price and bought it wothout knowning any thing about it. Initially I thought if might have been by Alphonse Cyteres; a French pottery working at Rambervillers in the early 20th C, but I soon realized that whilst the style of signature was similar it was not the same. Looking in my books, many French potters had similar script marks with long tails.
My first stop for continental pottery and faiences is always my friend Alan at www.mayfieldpottery.com he always has a selection of interesting pots for sale. Yes, straight away I found pottery marked Guerin which looked very similar. A bit of googling later and I'm sure it is by the pottery Roger Guerin 1896-1954.
Roger Guérin was Belgian potter from the village of Bouffioulx. He started his own workshop in 1918 with his son Jules Guerin taking over in about 1945. Dating seems to be a problem, generally accepted that incised "R Guerin" marks are earlier with simple Guerin signatures, some impressed, are after c1925. Items marked Gres d'art R. Guerin Bouffioulx are probably about 1930. Roger appears to have exhibited his pots Paris during the 1930's and he was a member of the Socieate des Gres d'art de Bouffioulx.
Here are a few more found on Google.
These are beautifully made pot and some are quite large and impressive looking. The prices on some of the American site are staggering $500-600 for larger ones else where like at Mayfield Pottery the prices for smaller examples are typically £30-50 each. I would guess that these would not be to current UK tastes as large brown pots are not a colour currently in vogue. Bring back the enthusiast who buys for the artistic and technical merit.