LONDON: Wal-Mart has been named as the most valuable global brand in a study by Brand Finance, which also reports that the net worth of the top 500 biggest brands worldwide fell by almost a quarter during last year as a whole.

The US retail giant was ranked in third place in Brand Finance's previous annual list, but took the number one spot in 2008, and is now valued at $40.6bn (€30.6bn; £27.6bn).

It was followed in the rankings by Coca-Cola (valued at $32.7bn), IBM ($31.5bn), Microsoft ($30.8bn) and Google ($29.2bn).

However, the net worth of the world's top 500 brands fell from $2,996bn in 2007 to $2,289bn last year, down 24% on an annual basis.

Brands based in the US took each of the top six places, as well as making up a total of 29 of the top 50 global assets.

They also contributed 44% of the overall value of the global top 500, and were responsible for 58% of the decline in value of this group last year, at $411bn.

Brand Finance reports that the number of Asian brands in the rankings rose by 13 compared with 2007, while there were six fewer brands based in Europe and 17 less headquartered in North America.

Telecoms overtook banking as the single most valuable sector, after the latter category posted a 33% decline in its net worth.

In all, however, the financial sector still housed the highest number of companies in the top 500, at 77, followed by retail, with 57, and telecoms with 49.

Data sourced from M&MGlobal/Daily Mirror (Sri Lanka); additional content by WARC staff