The Securities and Exchange Board of India has started investigating abnormal trading volumes in the Indian Oil Corporation scrip prior to the announcement of the 1:2 bonus issue. With this, Sebi has extended the scope of its ongoing inquiry into the rise in bank scrips.

Sebi has also included in its investigations the Industrial Development Bank of India scrip, whose price trebled in recent times.

The market regulator's investigation department sent out an urgent letter to all market intermediaries, including mutual funds, foreign institutional investors and brokers, demanding details of investments made in select stocks -- Punjab National Bank, Oriental Bank of Commerce, Bank of Baroda, Canara Bank, Bank of India, IDBI, IFCI and IOC.

The intermediaries are reported to have furnished all details last evening. Sebi had asked them to furnish details of transactions where they had purchased more than 20,000 shares in any of these scrips between April 1 and June 6.

It had also sought full details from investors who had made purchases of Rs 10 lakh (Rs 1 million) and more in each of these scrips between March 1 and June 6.

Sebi had asked the intermediaries to furnish details of their shareholding on March 31, 2003, in these scrips, the date of purchase or sale and holding in these stocks on June 6.

The urgency in seeking details of transactions follows Finance Minister Jaswant Singh's concern over the volatility in bank stock prices.

During his visit to Mumbai, Singh had said Sebi had been asked to submit the report on bank stocks on priority.

Stock prices of bank shares have been highly volatile in the past few weeks, fuelled by statements by some banks that they will return capital to the government to boost valuations.