The main objective of the group is for members to reduce outer carton packaging by a minimum 25 per cent in weight.
It is hoped that this can be achieved by working towards standardised external dimensions, which members can voluntarily adopt, WRAP said.
Initially, the group will look at ways to reduce packaging for medium-sized Easter eggs, but said it is collaborating to find ways of reducing seasonal confectionery packaging without compromising brand perception.
The group intends to promote a widespread packaging reduction programme for seasonal confectionery and share findings with industry players to effectuate and accelerate change.
Group members remain free to pursue their own packaging reduction projects.
According to WRAP, members of the group already include Mars UK, Cadbury-Trebor-Basset, Nestlé UK, Kraft UK and Magna Specialist Confectioners.
WRAP invites other brands or confectioners to join.
Mark Barthel, special advisor for WRAP, is quoted as saying: " Major players in the seasonal confectionery industry have signed up to this group.
By joining, they are ensuring that issues relating to packaging are taken into account and that consumer appeal is retained.
This will in turn ensure changes can be made across the industry .
Because of the long lead-times involved in seasonal confectionery production the results of the group's deliberations will not be seen on retailers' shelves until Easter 2009.
According to WRAP, packaging generated from Easter eggs amounted to about 3000 tonnes in 2006.
Packaging weight data suggests that if all eggs were changed to the current lightest packaging up to 680 tonnes less material would be required per year.
WRAP said: " This initiative seeks to accelerate activities in this area and promote best practice so that these potential material savings can be realised ."
In line with the group's proviso that companies can pursue their own packaging reduction projects Cadbury Schweppes is testing an unboxed chocolate egg in the UK this year, after customers asked the company to be more environmentally friendly.
Cadbury spokesperson Tony Billsborough told ConfectioneryNews.com last month that the new foil-wrapped eggs would be sold under the Mini Eggs, Dairy Milk and Dairy Milk Caramel brands.
The only other packaging involved would be the cardboard moulding casing used to stand the eggs upright on the shelves.
He added that between two and three million of these eggs have been made this year, about 10 per cent of all Easter eggs made for the UK market.
WRAP works in partnership to encourage and enable businesses and consumers to be more efficient in their use of materials and recycle more often, to minimise landfill, reduce carbon emissions and improve the environment.
It is backed by government funding.