LONDON (AP) - Prudential plc., Britain's biggest insurer by market value, said its first half loss narrowed after a strong rise in US sales and an increase in the value of the securities it holds. Shares in the company jumped eight percent.

The net loss of £129 million ($213.6 million) in the first half compared with a £355 million loss in the first half a year ago.

Chief executive Mark Tucker said performance improved because of a focus on capital conservation and expanding sales.

The company's US sales were the best in the company's history, rising 10 percent to £392 million. In contrast, revenue from new business in Britain dropped 14 percent to £376 million and Asian sales lost 15 percent to £553 million.

"While we expect the business environment to remain difficult through the rest of 2009, Prudential is very well positioned to take advantage of any improvement in market conditions," Mr. Tucker said in a statement.

Prudential reported so-called comprehensive net income, which - in accordance with revised accounting rules - includes exchange and valuation movements that were previously excluded.

The net loss as reported under the old accounting rules more than doubled to £254 million, from £116 million.

Operating profit, the figure most closely watched by analysts, fell 7.7 percent to £1.25 billion - a better result than analysts had forecast.

"Prudential has confirmed its credentials as a leader in its space with a set of numbers which surpassed expectations," said Richard Hunter, head of UK equities at Hargreaves Lansdown Stockbrokers.

"In particular, the drop in operating profit was less than feared, whilst the capital cushion has doubled since the end of last year," said Mr. Hunter. "Meanwhile, the group's geographical diversification continues to benefit the figures, especially in the US."

Manoj Ladwa, senior trader at ETX Capital, said the company's strategy started last year to conserve cash and focus on the best product lines "seems to be paying off against a backdrop of turmoil in the sector".

Mr. Ladwa also noted that the company was increasing its first-half dividend - to 6.29 pence from 5.99p - at a time others in the insurance industry were cutting dividends.

"So it is steaming ahead," he said.

Prudential shares were up 38.20p at 516.5p in midmorning trade on the London Stock Exchange.

The company announced earlier this year that Mr. Tucker, who has led the company for four-and-a-half years, will be replaced on October 1 by the chief financial officer, Tidjane Thiam.