By Paul Sandle

LONDON (Reuters) - Shareholders in British technology company ARM approved its sale to Japan's SoftBank on Tuesday, marking the end of independence for the chip designer that powered the smartphone revolution.

SoftBank swooped on the Apple supplier in July, agreeing to pay $32 billion in cash for a company that it hopes will remain at the forefront of digital innovation.

ARM said that more than 95 percent of the votes cast on Tuesday approved the takeover.

Seeking to win political backing and smooth the path for the deal, the Japanese company's charismatic leader Masayoshi Son spoke to British Prime Minister Theresa May shortly before the deal was announced to allay concerns that it would be bad for the British technology sector. SoftBank, which is paying a 43 percent premium, has promised to at least double ARM's workforce in Britain over the next five years, keep its headquarters in Cambridge and retain its partnership-based business model and culture.

The commitments will be the first test of new takeover rules that make such pledges binding. The rules were introduced after Pfizer attempted to buy Britain's AstraZeneca in 2014.

ARM Chairman Stuart Chambers said that SoftBank's guarantees on jobs and investment were legal commitments, not merely "nice ideas and promises and intents".

"If you look at the post-offer undertakings that SoftBank has made, they are extremely strong, they are virtually unprecedented," he told Reuters after Tuesday's shareholder meeting in London.

Chief Executive Simon Segars, who will stay with the company, said that SoftBank shared ARM's long-term view on investment, including retaining and developing the engineers who were essential to ARM's success.

"We are not going anywhere, we are still going to be at the heart of British technology. We are growing globally because we are a global business," he said.

"This represents an exciting new chapter for ARM, and an ability to really grow and do everything we were doing and do more and do it faster."

Some remained unconvinced, however. Paul Myners, a former British financial services minister, said the sale was more evidence of the City's predilection to "sell at a reasonable premium, get out, don't invest for the future, don't back the British economy".

"This is a business that is at the heart of the ecosystem of modern technology, the internet of things, an area in which we lead," he told BBC radio on Tuesday, adding that it would not have been possible to sell ARM in 60 days had it been an American, German, French or Japanese company.

"We will not have world-beating companies if we continue to sell out our leaders at such an early stage," he said.

(Editing by David Goodman)