* UN says one third of food produced is wasted
* EU wants to halve food waste by 2020 from 90 mln tonnes
* Tesco to end multi-buy offers, remove 'display-until' labels
* Nestle targets zero waste in European factories
* Austrian, Swiss stores sell misshapen produce
BERLIN, Oct 7 (Reuters) - Tesco, Britain's biggest retailer, vowed on Monday to cut the near 60,000 tonnes of food wasted by its suppliers and shoppers each year, the latest firm volunteering to help tackle a growing environmental problem.
The U.N. Food and Agriculture Organisation said last month that a third of all food produced worldwide, some 1.3 billion tonnes worth $750 billion, is thrown out each year, wasting water equivalent to the annual flow of Russia's Volga River.
Tesco said it was the first British retailer to reveal data on its food waste, which it put at 28,500 tonnes in the first half of the year. In total the Waste and Resources Action Programme (WRAP) estimates Britain wastes 15 million tonnes of food each year.
The European Union is seeking to halve the disposal of edible food waste in the bloc by 2020 from about 90 million tonnes currently, by donating surpluses to food banks, reviewing "sell-by" date labelling and shortening supply chains.
"Families are wasting an estimated 700 pounds ($1,100) a year and we want to help them keep that money in their pockets, rather than throwing it in the bin," Matt Simister, Tesco's group commercial director for food, said in a statement.
Nestle, the world's biggest food company, pledged last week to achieve zero waste in all of its 150 factories in Europe by 2020 in a campaign which will include using spent coffee grounds as a source of energy at its Nescafe factories.
For its part, Tesco said on Monday it would end multiple-buy offers on large bags of salad after data showed that 68 percent of all salad grown to be sold in bags ended up wasted. It is also cutting the amount of bread on display and sharing tips on how to use leftover loaves.
The world's third-biggest retailer behind France's Carrefour and U.S. number one Wal-Mart is trying to improve its image in its main British market, where it has been losing market share in recent years.
Tesco said 40 percent of apples, a quarter of grapes and a fifth of bananas were wasted, prompting it to work with growers to reduce pests and disease and trial new varieties, as well as improving transport and sharing storage tips with customers. It will also remove "display until" dates from fresh produce.
The British government says confusing labelling is partially to blame for food waste and wants to phase out "sell-by" or "display-until" labels used by stores for stock control.
A study published last month by Harvard Law School and the Natural Resources Defense Council found that dates printed on U.S. packaged foods are inconsistent, confusing consumers and leading many to throw out food before it actually goes bad.
Environmentally-aware Germany has taken the lead in fighting food waste in Europe, with the government launching a "too good for the trash" campaign last year. The country is also a pioneer in "food-sharing", using the Internet to distribute produce recovered from store rubbish while still in good condition.
Meanwhile German grocery chain Rewe started a trial in Austria this month to sell less than perfect apples, carrots and potatoes as part of its contribution to reducing waste, while Switzerland's Coop has launched a "unique" range of oddly-shaped produce.