Ian Aley, head of pension transactions at Towers Watson, explained in a telephone interview that the transaction had broken new ground on two levels. "It is a new party taking the risk, in Aviva," he said. "And unlike the transactions that we have seen to date, where longevity risk has been written by the insurer or bank and passed entirely to the reinsurance market; here the counterparty — Aviva — is retaining an element of the risk."