Mars has crashed 20 places down the list of Britain's 100 biggest brands despite pumping millions into a World Cup tie-up and slashing the fat content of bars.

Sales of the 79-year-old brand have slumped 14.2% a £17m fall in value while volume has plummeted 13.9% [Nielsen 52w/e 25 December 2010], according to The Grocer's Britain's 100 Biggest Brands survey published this week. In contrast, sales of all other leading chocolate confectionery brands have risen.

In January last year Mars announced it would be reducing the satfat of its chocolate bars by 15% by summer 2010, following five years of research and a £9m outlay. During England's disastrous World Cup campaign, Mars suffered alongside the team having signed a five-year sponsorship deal with the FA in October 2009 and repackaged bars in a white wrapper with the St George cross. It also brought in John Barnes to reprise his 1990 World In Motion rap for an ad, part of the £7.4m ad spend on the brand over the year [Ebiquity].

Nielsen, which supplied the sales data for the survey, says much of Mars' decline is down to a drop in sales of Mars Delight and Mars Planets, although novelty and Easter lines have done poorly and sales of the Mars bar itself have fallen about 6%. Mars declined to comment, but said its product remained "the number one substantial brand in the UK".

According to brand experts, however, Mars has failed to keep pace with trends in chocolate confectionery, which some say has become more sophisticated and geared towards premium, more feminine products. "Mars is looking a bit past its sell-by date," said Richard Buchanan, director of branding agency The Clearing. "Look at its black, red and gold branding it is the Ford Capri of chocolate bars. It oozes masculinity."

Buchanan said PR and marketing for the potential health benefits of chocolate had split the market into "good" products that are dark and high in cocoa, and "bad" ones high in fat and sugar. "In Scotland, they're not putting Green & Black's Espresso bars in deep-fat fryers they're using Mars bars," he added. "That sort of negative image is very damaging to a brand."

He said the brand had not made enough noise about cutting its satfat content although Mars has said the move was "the right thing to do for consumers" and not a sales driver. The brand's football tie-up has also come in for criticism. "Tying into the World Cup was one hell of a gamble," said Tim Orrell, MD of Golley Retail. "It's aligning your fortunes with something you have no control over."

Mars has said much of this year's £9m ad budget will go towards a football-themed Win & Play with your Heroes campaign.

Britain’s 100 Biggest Brands: winners and losers

Position: 55 (up 14)
Sales: £123.7m (+£21.2m)
Change: +20.7%

Cadbury biscuits
Position: 92 (up 22)
Sales: £88.2m (+£21.5m)
Change: +32.3%

Position: 73 (down 20)
Sales: £102.1 (-£16.8m)
Change: -14.2%

Position: 104 (down 19)
Sales: £74.7m (-£13.7m)
Change: -15.5%

Source: Nielsen 52w/e 25 December 2010