Standard Life members yesterday agreed to end 80 years as a mutually-owned company in a historic vote.
More than 1.5 million members voted 98 per cent in favour of plans for a stock market flotation at a special general meeting of the insurance and investment business.
If carried out, it would see about 2.4 million members - about 111,000 of whom live in the West Midlands - receive an average windfall of around £1,700.
At the meeting in Edinburgh, a total of 1,577,788 votes were received, with 1,545,314 for demutualisation and 32,474 against.
Policy holders had been asked to decide on one resolution - "to demutualise and float on the London Stock Exchange".
The company's chairman Sir Brian Stewart immediately hailed the vote as great news for the business.
Opening the meeting, Sir Brian had urged members in the audience still to make their decision to vote in favour.
He said demutualisation would unlock the value of the business for policy holders and allow it to raise more capital on the financial market.
"It is a historic day for Standard Life, it's the beginning of another phase in Standard Life's history. We believe it will provide significantly more opportunity for the development of Standard Life and is in the best interests of members, customers and policy holders.
"We will be as committed as a Plc as a mutually owned company."
During the meeting the board faced a series of questions from members, some of whom had travelled from across the country to attend.
Concerns over the cost of the demutualisation process, the maximisation of any subsequent share price and the proportion of the company that will be owned by members were raised.
One questioner also accused the board of presenting a fait accompli to policyholders.
After the meeting, Peter Ware, from Woking, Surrey, said he had opposed the move from the start and thought members had lost a part of history by being too easily swayed by the prospect of a windfall.
The 38-year-old catering manager said: "I actually think it's a sad day.
"Everybody just seems to be interested in how much money they are going to make."
But businessman Yuill Young, 65, from Ayr, said he believed the move would boost the company in the years to come. He said: "There's no question it will take the company forward. I think the company can go forward with confidence."
Management needed the support of at least 75 per cent of voters and had been hoping for a turn out of at least one million to prove demutualisation had sufficient support.
The decision had been widely predicted due to the number of people in line for a windfall.
About half the membership will earn £500-£1,000 from the flotation, with the remainder collecting in excess of that.
The windfalls will be largest for people who took out a with-profits policy a long time ago and have invested significant sums in it since then.
Postal voting closed at midnight on Sunday, with the final votes cast by members at the meeting minutes before the outcome was flashed up on a screen. Court approval will be needed during a June hearing before stock market listing can go ahead.
More details on the subsequent flotation, which could happen in July, are expected to follow. It is likely to value Standard Life at between £4.8 billion and £5.5 billion.
The company has just over £124 billion of funds under management and has reorganised its business to prepare for the listing.
Figures released on Tuesday showed first quarter profits from new business at a better-than-expected £30 million compared with £33 million for the whole of last year.
Yesterday's events were a radical turnaround for Europe's biggest life office, which spent more than £10 million on defending its once cherished mutual status against carpetbaggers in 2000.
Since then, however, the society has been badly hit by stock market losses and has been forced to rebuild its balance sheet to comply with new Government funding regulations.