The outsourcing deal was announced at the end of last year, and is expected to result in thousands of Prudential staff transferring to Capita as part of the deal.
The agreement involves the delivery of life and pension sales and administration services during a 15-year period.
"This agreement represents a milestone for both Prudential UK and Capita, further cementing Capita's position as the market leader in insurance BPO processing in the UK, and serving as a critical component of Prudential UK's ongoing transformation programme," said John Keppel, partner for global financial services at TPI.
TPI said the deal, an extension of the two companies' existing relationship, will result in the transfer of over 3,000 employees in the UK and India to Capita, and the sale of Prudential UK's Mumbai-based operation.
Gary Shaughnessy, managing director for retail life and pensions at Prudential, said, "TPI provided us with valuable advice through a very important and sensitive process for Prudential UK.
"By running a streamlined and detailed process to identify the right service provider, developing and negotiating a contract and counseling us through transition, TPI has enabled Prudential UK to enter into a cost effective, efficient and truly strategic outsourcing partnership."
TPI's insurance practice group has advised Zurich UK, RSA, Aon, Zurich Group, Standard Life and Axa.