Apple has extended its lead as the world's most valuable corporate name with a strong 19 percent increase in its so-called brand value, a survey showed Tuesday.

The research firm Millward Brown Optimor, a unit of advertising and communications giant WPP, found that Apple's brand value increased 19 percent to $182.9 billion, holding the top spot for the second straight year.

IBM's brand value grew 15 percent to $115.9 billion and overtook Google, which dropped to third place at $107.8 billion.

The survey attempts to determine a brand value, separate from a company's stock market value, by calculating earnings potential and other intangible factors.

In advance of its share offering, Facebook rose 74 percent in value, the strongest increase. Worth $33.2 billion the social network moved up to number 19 from number 35, the survey concluded.

The BrandZ survey showed the top 100 global brands rose 66 percent since 2006 and are now worth $2.4 trillion.

"Brands are an insurance policy for businesses," said Eileen Campbell of Millward Brown.

"Despite a prolonged period of economic stress, political uncertainty and natural disasters that buffeted brands across many categories, the value of the world's leading brands keeps rising across many categories, sustaining and nurturing businesses."

David Roth of WPP said Apple continues to innovate and maintain its "luxury" brand status, but faces future competition from firms such as Samsung, which has a brand value of $14 billion.

"Samsung is successfully outpacing Apple in a significant number of markets by positioning as a cool, well-priced alternative to the ubiquitous iPhone," he said.

The top 10 in the survey, based on consumer analysis in numerous countries, was dominated by US firms.

In fourth place was fast-food giant McDonald's with a brand value of $95 billion, followed by Microsoft ($76 billion), Coca-Cola ($74 billion), Marlboro ($73 billion), AT&T ($68 billion) and Verizon ($49 billion).

The only non-US brand in the top 10 was China Mobile, worth $47 billion.