LONDON (Reuters) - Silicon Valley technology giants such as Facebook and Google have grown so dominant they may need to be broken up, unless challengers or changes in taste reduce their clout, the inventor of the World Wide Web told Reuters.

The digital revolution has spawned a handful of U.S.-based technology companies since the 1990s that now have a combined financial and cultural power greater than most sovereign states.

Tim Berners-Lee, a London-born computer scientist who invented the Web in 1989, said he was disappointed with the current state of the internet, following scandals over the abuse of personal data and the use of social media to spread hate.

"What naturally happens is you end up with one company dominating the field so through history there is no alternative to really coming in and breaking things up," Berners-Lee, 63, said in an interview. "There is a danger of concentration."

But he urged caution too, saying the speed of innovation in both technology and tastes could ultimately cut some of the biggest technology companies down to size.

"Before breaking them up, we should see whether they are not just disrupted by a small player beating them out of the market, but by the market shifting, by the interest going somewhere else," Berners-Lee said.

Apple, Microsoft, Amazon, Google and Facebook have a combined market capitalization of $3.7 trillion, equal to Germany's gross domestic product last year.

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Berners-Lee came up with the idea for what he initially called "Mesh" while working at Europe's physics research center CERN, calling it the World Wide Web in 1990.

When asked who had the biggest intellectual influence on him, he said: "Mum and Dad."

"They were building computers, so I grew up living in a world where everything was mathematics and the excitement of being able to program something was very fresh," he said.