The strong Australian dollar, competition from overseas online retailers and cautious consumers combined to take their toll, Brand Finance Australia found in its annual study into the value of household brand names.

David Jones and Harvey Norman suffered the largest falls in 2011 - shedding 20 per cent, or roughly $100 million each - from their brands, while Bunnings and Target rose up the ranks, benefiting from strong customer loyalty and keen pricing.

Qantas dropped below the $1 billion mark for the first time - a significant milestone for an Australian icon which strained the loyalty of its customers following its decision to ground its planes last year.

Brand Finance Australia's managing director, Tim Heberden, said: ''If one is looking for good news then this year's drop of $108 million [for Qantas] represents a reduced rate of decline.''

Woolworths remained in the top spot for the second year running, despite losing half a billion dollars from the value of its brand - more than any other company - due to the fact that its sales are slowing down. Meanwhile, the brand value of Coles rose by a similar increment to come in at number three overall.

Brand Finance calculates a brand's value by looking at a company's market share, profitability, reputation and emotional connection with consumers and then figures out what that company would pay to licence the brand if it was owned by a third party. Overall the top 30 Australian brands held their value at $50 billion.

Woolworths' brand, for example, represents a little over a quarter of the company's market capitalisation, or total value.

While the figures may seem large, they are dwarfed by comparison to large international brands such as Apple, which is regarded by any measure as the world's most valuable brand. Brand Finance valued the technology company's brand at $US71 billion ($71.5 billion), which is nearly 1½ times the combined value of the top 30 Australian brands.

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