Standard Life has cut payouts on millions of pensions and endowment policies as fears spread about insolvency across the industry.
The mutual insurer said that falls in the stock market had forced it to cut maturity payouts by 10% and impose an additional 10% penalty on early payouts.
Finance director John Hylands said: "This decision has been taken in response to recent investment market conditions, not as a result of any deterioration in the company's financial position, which remains strong and secure."
Standard Life has not confirmed whether it is going to sell out of equities and instead switch into bonds to shore up its capital position.
A spokesman said: "Our last stated asset mix in June was 73% equity. In the next two weeks we will release our latest asset mix.
"We are not prepared right now to discuss what measures may or may not have been taken to change the asset mix."
