Retailers are fighting it out over who will gain the biggest slice of the Hallowe'en market in what is emerging as one of the key trading periods of the year.

Hallowe'en is now worth £100m annually to UK retailers, said Karl McKeever, brand director of merchandise consultants Visual Thinking. "Hallowe'en accounts for 5% of all seasonal sales. It falls at the right time between back-to-school and Christmas," he said.

McKeever said Asda was best placed to take advantage of the festival's growing popularity in the UK.

"This year we believe Asda will be the winner in the Hallowe'en market. You can see the American influence from Wal-Mart and the product range is a lot better, the aisles are wider and it has invested more in promotion, such as a big grim reaper holding an axe.

"The only thing Asda falls down on is that it puts its costumes in the George clothing section, meaning shoppers may not see it."

McKeever said that rival retailer Tesco scored highly by placing seasonal goods near the entrance.

"This is where it makes extra money as Tesco gets you to spend that extra £3 or £4 before you have even started shopping," he said.

McKeever visited a representative sample of supermarkets in Nottingham and Leicester to assess offer, placement and visual impact.

This month, Asda retail director Andy Clarke said Hallowe'en was Asda's second biggest trading period after Christmas and claimed it "owned" the event.?