The firm is looking to raise $20.9 billion to help fund the acquisition of AIA, the Asian unit of American Group International.
Prudential’s acquisition of the division is expected to cost $35.5 billion.
The rights issue was due to go-ahead last week but was delayed after the Financial Services Authority failed to provide the firm with its approval due to concerns over capital reserves.
Tidjane Thiam, Prudential chief executive, said: “We have the team, the skills and the discipline to successfully integrate these businesses and achieve the targets we have announced today.
"We believe that, through capital management and portfolio rationalization, there will be opportunities for the combined entity to create additional shareholder value over and beyond the revenue and cost synergies identified.”
If the acquisition of AIA is successful, the merged business could be worth $60 billion by 2013, the Prudential has claimed.
Meanwhile, the firm released financial figures for the first quarter of 2010, which revealed that group-wide new business sales were up by more than a quarter when compared with figures from the same period in 2009.
Sales of new business reached £807 million in the first three months of the year.
By Jim Ottewill