Cevian revealed a 4.95% shareholding in June and said it wanted Aviva to return GBP5bn of excess capital to shareholders.
Earlier this month the insurer said it would return cash, but indicated a figure closer to GBP4bn.
Cevian said that was “a good start” but was not enough “to address the overcapitalisation” of the company.
Aviva has cash to hand out following a whirlwind GBP7.5bn disposal programme that has seen it pare down its global operation to just the UK, Ireland and Canada.
Those disposals enabled the insurer to repay GBP2bn in debt in the first half of the year, with a further GBP1.7bn to follow.
When it announced its stake in June, Cevian said that in addition to a GBP5bn return of capital, it wanted to see GBP500mln of cost savings (against a company target of GBP300mln), a doubling of the dividend to 45p and a share price of GBP8 within three years.
Aviva shares today were up 0.3% at 420.8p.