Life insurer Standard Life on Wednesday reported a smaller-than-expected 10 percent rise in nine-month sales and said its capital strength had been largely unaffected by financial market turmoil triggered by the eurozone sovereign debt crisis.

Standard Life, Britain's fifth-biggest life insurer, said it had long-term new business sales of 15.5 billion pounds in the first nine months of 2011, up from 14 billion pounds in the same period last year.

Analysts had expected sales of 15.8 billion pounds, according to a consensus forecast compiled by the company.

Edinburgh-based Standard Life added that its capital position had been largely insensitive to sharp falls in stock markets this summer thanks to efforts to de-risk its capital reserves.

Although the economic backdrop continues to be uncertain the outlook for our business is positive, Chief Executive David Nish said in a statement.

Standard Life shares closed at 206 pence on Tuesday, valuing the company at about 4.8 billion pounds. The stock is down 4.6 percent in the year to date, outperforming a 15.5 percent decline in the European insurance share index <.SXIP>

(Reporting by Myles Neligan; Editing by Sudip Kar-Gupta)