LONDON (Reuters) - Insurer Standard Life (>> Standard Life Plc) reported strong net inflows in the first nine months but said that changes in British pension rules cut sales of key products and made the outlook uncertain.

The government's Budget changes in March mean that British savers will be given more access to their pension pots, with no obligation to buy an annuity, with further changes this month making it easier for over-55s to withdraw money from their pension schemes.

Paul Matthews, chief executive of Standard Life's British operation, told reporters that a 50-60 percent drop in annuities - which provide savers with an income in retirement - is expected but the full impact will remain unclear until all the changes come into force next year.

Life insurance companies have been focusing on the sale of other products, such as drawdown schemes, which enable holders to withdraw money from their pensions.

"We do not know how many are going to go into (pension) drawdown," Matthews said.

Shore Capital analyst Eamonn Flanagan described the statement as cautiously upbeat, reiterating his "hold" recommendation on the stock, while Gordon Aitken of RBC Capital said he expected Standard Life to be less hurt by falling sales of individual and bulk annuities than rivals Legal & General (>> Legal & General Group Plc) and Friends Life (>> Friends Life Group Ltd).

Standard Life's net inflows were 4.3 billion pounds in the first nine months, with assets under administration from continuing operations rising to 290 billion pounds from 237.6 billion pounds a year ago, the company said in Wednesday's trading update.

The figures were helped by the sale of Ignis Asset Management, it said, while it classed its Canadian operations, which it sold during the third quarter, as discontinued operations.

Quarterly sales of UK annuities plunged 67 percent year on year, with sales this year down 55 percent, sending the company's shares down nearly 2 percent to 379 pence in early trading.

(This corrected version of the story fixes time period of net inflows to nine months).

(Editing by David Goodman)

By Carolyn Cohn