AstraZeneca's Crestor is emerging as a potential big winner in the fiercely competitive anti-cholesterol market, with two brokerages on Tuesday hiking sales forecasts for the drug to $8-9 billion.

Shares in the Anglo-Swedish group, which have been hit recently by fears of generic competition to its top medicines, jumped for a second day, adding 5.5 percent by 1200 GMT, the biggest daily gain in more than four months.

Japan's Shionogi & Co Ltd, which originally developed Crestor, soared more than 9 percent.

JPMorgan said positive results from a clinical trial of Crestor in certain patients with low or normal cholesterol could lift worldwide annual sales to $9 billion by 2016.

That is more than three times the $2.8 billion sold in 2007 and 50 percent above the brokerage's previous 2016 estimate, prompting it to lift its stock recommendation "neutral" from "underweight".

Dresdner Kleinwort analysts raised their 2012 sales forecast to $8.3 billion from $5.5 billion on the back of the decision to end the so-called Jupiter study early because of good results, which was announced on Monday.

For AstraZeneca, the timing could not be better. The surprise good news for Crestor, its third-biggest product, contrasts sharply with criticism from leading cardiologists at a weekend medical meeting of Merck & Co and Schering-Plough's rival product Vytorin.

Unlike Crestor, Vytorin has failed to show benefits in clinical outcome trials.

Investors have yet to see the scale of the improvement in patient outcome in the Jupiter study, which involved 15,000 people. But the surprise decision to end it early because of "unequivocal evidence of a reduction in cardiovascular morbidity and mortality" stands to give AstraZeneca a big advantage. - Reuters