Insurer Aviva has reported rapid progress in integrating the acquisition of Friends Life.

The £5.6 billion deal is a key part of a turnaround led by chief executive Mark Wilson.

Mr Wilson said the restructuring is ahead of schedule and indicated the integration of Friends Life has started "at pace".

The company previously announced that it will close the Friends Life head office in London, and that it will move to smaller premises in Exeter. There is no information on how many jobs may be lost as a result.

Aviva, which employs 2,500 people in its general insurance business in Perth and Bishopbriggs near Glasgow, has previously indicated it expects there to be around 1,500 job losses as a result of the acquisition.

Aviva, which says the merger creates a UK market leader in life insurance with 16 million customers, also saw first-quarter gains in the key measures of its life and general insurance businesses.

Its value of new business grew 14 per cent to "247 million from a year earlier, though the value of new business for annuities fell 60 per cent. Its combined operating ratio improved by 1.3 percentage points to 96.4 per cent. A number below 100 per cent indicates a profit.

Mr Wilson said: "This is a satisfactory set of results, in particular our UK businesses have performed well."

He added the company would be disappointed if it did not generate at least £225m in annual cost savings through the Friends Life deal by the end of 2017.

JP Morgan reiterated its "buy" recommendation on the stock, saying Aviva was a "strong restructuring story with potential for organic growth, post-Friends Life integration".

Separate data for Friends Life showed the value of its new business fell 37.5 per cent to £20m.