I've owned a couple of these vases in the past - albeit only in pink or clear frosted - I've never seen one in this cobalt blue before. They turn up every so often in France and are usually attributed to Pierre d'Avesn. that said, I've never seen a marked example, nor found the vase in any catalogue, so the attribution may just be wishful thinking (though the design shows strong stylistic similarities to some known d'Avesn vases).
If not d'Avesn, then it could well be Czech - the way the rim is formed reminds me of some Libochovice mould-blown vases, but I wouldn't rule out France, Belgium or even Poland.
