Shares of AstraZeneca Pharma India soared 20 per cent to hit the upper circuit on the BSE on Monday after the company announced a proposal to delist its shares from the Indian stock exchanges, but many dealers and traders are skeptical of the proposal's success.

Those who are doubtful of the plan's success are thus advising investors to stay away from the stock because it would hit bottom in a flash in case the proposal is derailed.

Market experts say that it would not be an easy task for pharmaceutical major AstraZeneca Pharmaceuticals AB's India unit to delist its shares from the Indian stock exchanges considering that very high expectations have derailed similar efforts by the Anglo-Swedish pharmaceutical maker in the past.

Sarabjit Kour Nangra, vice-president (research-pharma) at Angel Broking, said that investors are looking at a minimum of 15-30 per cent premium over the shares' current market price to allow delisting plans to succeed, which would not be easy to execute for the company.

A trader said investors would unlikely to tender shares of AstraZeneca Pharma India even at Rs 1,400 apiece.

Previously, the company announced its plans to delist shares twice - in 2004 and 2010, but shareholders turned down both of its share buyback proposals. Some market experts are optimistic that given earlier failed attempts, company will gladly offer a lucrative price of Rs 1,400-Rs 1,500 per share this time.