Protests by a small group of Norwich Union shareholders against the massive insurer's £18bn proposed merger with CGU were brushed aside at a special meeting which endorsed the deal.
A minority of up to 200 NU shareholders attending Friday's special meeting felt the terms of the deal were more favourable to CGU shareholders and that the nil-premium deal was a takeover by CGU in all but name.
Michael Braham, a chartered accountant and NU shareholder, criticised the ratio of shares he was being offered in the new company CGNU.
"I think you have delivered a terrific deal to CGU shareholders. I think you have sold us down the river," he told NU's board.
NU shareholders are set to be given 48 shares in the new entity CGNU for every 100 NU shares.
Richard Harvey, chief executive of NU, said the rate of exchange was fair as it was based on the two insurers' relative market capitalisation over the past year.
He went on to re-state the board's argument for the merger, saying if NU failed to consolidate in the UK, it would encounter increasing difficulty in competing with European insurers.
The result of the shareholder vote was an overwhelming win in favour of merger. It was approved by 91.8% of NU shareholders who voted, to 8.2% against. The merger is expected to become effective by June 2000.