* UK Plastics Pact launched
* 42 companies pledge cuts to plastic use by 2025
* Signatories include Tesco, Nestle, Procter & Gamble
LONDON, April 26 (Reuters) - More than 40 companies, including Britain's biggest supermarkets, Coca Cola, Nestle and Procter & Gamble, have bowed to growing pressure to tackle pollution by committing to cut plastic use over the next seven years.
The companies have promised to hit a target by 2025 to eliminate unnecessary single-use plastic packaging in the United Kingdom.
Signing up to the UK Plastics Pact, launched on Thursday by sustainability campaign group WRAP, they have pledged that 100 percent of plastic packaging will be reusable, recyclable or compostable by that date.
Other targets are that 70 percent of plastic packaging is effectively recycled or composted, and that all plastic packaging will have 30 percent average recycled content.
Food and drink manufacturers and retailers around the world are under pressure to act on plastic waste given growing concern from the public and lawmakers about its damaging impact on the environment.
Prime Minister Theresa May has pledged to eradicate avoidable plastic waste in Britain by 2042 as part of a "national plan of action" and her government is looking at a range of options including banning some products and using the tax system to change consumers' behaviour.
The 42 Plastic Pact companies are responsible for over 80 percent of the plastic packaging on products sold through UK supermarkets, according to WRAP.
Market leader Tesco, Sainsbury's, Walmart's Asda, Morrisons, Marks & Spencer, discounters Aldi and Lidl have all signed up. Other signatories include the UK government and trade associations.
"Together, we have a once-in-a-lifetime opportunity to rethink and reshape the future of plastic so that we retain its value, and curtail the damage plastic waste wreaks on our planet," said WRAP CEO Marcus Gover.
In January, privately-owned Iceland became the first British supermarket to promise to eliminate plastic packaging from all of its own brand products and called on the industry to follow its lead.
Morrisons, Britain's fourth largest grocer, which unlike rivals makes about 30 percent of the food it sells, said on Thursday it would work through all of its own brand products to identify, reduce and remove any unnecessary plastic packaging.
It said black plastic trays used for fresh meat and fish will be phased out by the end of 2019, while customers will be allowed to use their own containers for produce purchased from its butcher and fishmonger counters.
Other measures include trialling the effect of removing plastic packaging from fruit and vegetables, with an aim to examine how plastic packaging, which helps keep food fresh, can be reduced without increasing food waste.
Tesco had already committed to making all packaging fully recyclable or compostable by 2025 and is targeting a halving of packaging weight by the same date compared to 2007 levels.
Sainsbury's has reduced its own brand packaging by 35 percent since 2005 and is targeting a 50 percent reduction by 2020.
Asda said in February it would use 10 percent less plastic in its own brand products over 12 months and had already committed to making sure all own brand packaging is recyclable by 2025.
Environmental groups have welcomed the food retailers' actions but have said they do not go far enough.
(Reporting by James Davey; Editing by Toby Chopra)
Our Standards: The Thomson Reuters Trust Principles.