Credit Suisse has signed an innovative longevity swap deal with a specialist fund manager, in the latest signal that a financial market may be taking shape that will allow participants to trade, or bet, how long populations are going to live.

Such transactions are comparatively rare, though the prospect of a tradeable longevity swap or bond has been mooted since at least 2004, when the French bank BNP Paribas tried unsuccessfully to launch a product.