Howard-Sneyd joined Direct Wines in February 2010 from Waitrose where he was head of wine.
His new business will be called Hive Wine Consulting, a name that complements his Domaine of the Bee winemaking project in Roussillon.
Direct Wines chief executive Simon McMurtie said: “Justin has done a fantastic job for us and I am delighted that Laithwaite’s will continue to benefit from his considerable creativity and energy.
“I fully support Justin’s ambition to spend more time speaking, writing, tasting and judging in the wider world of wine.”
Howard-Sneyd said: “It is fantastic to have the opportunity to invest more time in developing Domaine of the Bee and other winemaking projects, and I am looking forward to building up a list of other clients in the coming months.”