The three-year deal will see job agency Best International initially supply about 200 IT contractors to work on a range of Prudential IT services.
Best will provide a managed recruitment service for PruTech, which is an IT services arm of Prudential.
Analysts said the deal was one of the first of its kind for a large company. But they added that the success of the arrangement would only become clear over the next few years, because of the protracted skills shortage for IT professionals.
Prudential previously found its own contractors as well as using contractors from a range of recruitment agencies. The insurer claimed it will save £1m in "margin payments" for IT contractor fees in the first year of the contract with Best.
"It is an example of the large-scale changes taking place in the IT employment market and demonstrates the success outsourcing can bring," said Prudential's operations head of resourcing Yvette Hunt-Bingham.
Analysts said the cost savings appeared to add up, but the success of the deal hinged on the ability of Best to recruit IT contractors more effectively than Prudential's in-house recruitment department.