One of Prudential's largest shareholders has voiced his support for a break-up of the company, prompting talk of a possible merger with insurance titan Aviva.

The shareholder, who is said to be a fund manager with a substantial, long-held stake in the company, told Prudential’s chairman, Sir David Clementi, in a letter that splitting the business up could prove beneficial.

According to The Daily Telegraph, the letter does not directly call for a break-up but does say that the idea should not be dismissed, and suggests that there could be advantages to such a move.

The shareholder is not alone in this line of thinking as Prudential has been under increasing pressure from shareholders to take action to address its flagging UK operations, which have been underperforming for some time. Talk has previously focused on the possibility of Prudential selling off its UK arm and focusing more on its promising Asian business.

News of the letter has reignited rumors that Aviva could make a move for its compatriot. The insurer attempted a takeover last year, but this was rejected as Prudential saw a brighter future for itself as an independent firm. At the time of the bid, AXA, AIG and Generali were reportedly watching events closely.