The deadline for the 4.8-billion-euro (45 billion kronor) offer had been extended to January 12, 2006, the group added in an official statement.
Old Mutual, which launched its cash and shares bid for Skandia in September, had said it wanted to win the support of investors holding at least 50 percent of the Swedish insurer’s shares.
“I am delighted that holders of a majority of shares in Skandia have recognised the exciting potential of combining our two companies,” said Old Mutual chief executive Jim Sutcliffe.
He added: “I look forward to welcoming every member of Skandia’s staff around the world to the Old Mutual family”
A further statement on the total level of acceptances would be made on Wednesday, the group said.
On December 1, Old Mutual slashed its target level of shareholder support in the bid, which is being resisted by Skandia’s board, to 50 percent from 90 percent.
The group’s own shareholders have overwhelmingly backed the bid which is aimed at reducing the insurer’s dependence on South Africa and at creating the eighth-biggest insurance group in Europe.
In September, Old Mutual lodged its offer for 43.60 kronor per Skandia share, valuing Skandia at 44.9 billion kronor.
The offer deadline was initially set for November and had been extended to December 16.