Upmarket Belgian chocolate firm Guylian is moving further into block chocolate in the UK.

Guylian has begun testing a 200g dark chocolate bar after launching a 120g variant last month.

The chocolatier has also unveiled a range of festive products in the run-up to Christmas. The range includes Guylian famous praline seashells as well as Belgian truffles, La Trufflina.

The firm plans to promote the Christmas range with a GBP1.5m (US$3.1m) advertising campaign with the strapline: "Guylian. The world's favourite Belgian chocolates."