The Apple logo is now worth $39.3 billion according to Brand Finance

30 Top U.S. Brands. Click to enlarge. Source: Brand Finance

Microsoft (MSFT) is down 9% to $39 billion. Google (GOOG) is up 9% to nearly $48.3 billion. But Apple (AAPL) is way up -- 33% -- to overtake, for the first time, Microsoft, IBM (IBM), Wal-Mart (WMT) and General Electric (GE).

Those are the highlights of the interim brand value report issued last week by Brand Finance, a London-based consulting company that specializes in putting a dollar value what you might think is a rather intangible marketing concept.

Overall, the value of the world's top 100 brands have fallen 2.4% since January, according to Brand Finance, dragged down by the plummeting reputations of financial institutions like Wells Fargo (WFC) and Bank of America (BAC).

As if to prove there's some wiggle room in these valuations, a competing firm, BrandZ, put the value of the Apple brand at $153.3 billion in May, ahead of Google. (See How Apple became the world's most valuable brand.)

BrandZ bases its ratings, in part, on a survey of 2 million consumers. Brand Finance uses a more straightforward discounted cash flow technique to arrive at a net present value of a company's trademark and associated intellectual property.