Sainsbury's has announced plans to convert its entire banana range to 100% Fairtrade, saying it is the first UK retailer to do so. 

Sainsbury's said that the retail price of its bananas, the most popular item sold in supermarkets, would remain unchanged.

It will make the retailer's share of the entire Fairtrade market larger than all the other major supermarkets in the UK combined, it said.

As a result of the conversion, Sainsbury's said it will buy five times as many Fairtrade bananas from growers, creating a social premium of around GBP4m (US$7.8m) in 2007 to be returned to growers and their communities - an increase of over GBP3m on this year.

Sainsbury's chief executive Justin King said: "This move to 100% Fairtrade leads the world, and really sets the standard for global Fairtrade sourcing.   

"We will continue to give our customers great choice, at the same price, but from now on every customer will know that buying bananas from Sainsbury's is helping to make a difference to a developing country. Our buyer is working closely with the Fairtrade Foundation to support our growers in achieving Fairtrade status - we know our customers feel passionately about Fairtrade and we want to make their choice easier."

The company said that its customers currently spend GBP55m on Fairtrade products every year, with GBP25m of this is spent on bananas. Sainsbury's claims to sell 40% of all Fairtrade bananas in the UK.