The double-digit increase saw assets at the firm rise from £109bn to £121bn.
The company hailed the increase, which it said came “despite the major IT migration project undertaken during the period.”
Elsewhere in the business the figures were less rosy, with profits after tax falling from £716m in the same period in 2017 to £376m for the first half of this year.
Despite this the interim dividend was up 10% from 8.4p to 9.25p.
The firm said it had endured “choppy market conditions” in the period, but had achieved “attractive growth from its major businesses.”
Mark Wilson, Aviva group chief executive, said: “Aviva has grown operating earnings per share by 4% and increased the dividend by 10%.
“The 10% increase in the interim dividend is our fourth consecutive half-year of double digit dividend growth and further proof of Aviva’s progress.
“During these choppy market conditions, it is reassuring that Aviva’s results are consistent, dependable and growing.
"Aviva remains financially strong with a capital surplus of £11bn.
“In the first half of 2018, we started a £600m share buy-back and paid off €500m of expensive debt.
“We remain on track to achieve our financial targets.”