Some qualified institutional buyers seem to have cancelled their bids for the Oil and Natural Gas Corporation's public offer at the last moment.

Data culled from the Bombay Stock Exchange Web site this evening show a sharp decline in the total number of bids received by the issue.

The BSE Web site, which had pegged the total (BSE as well as National Stock Exchange) subscription to the ONGC issue at 1,170 million shares on Friday, brought it down to 920 million on Saturday and 860 million on Sunday morning, only to push it up to around 1,060 million on Sunday evening.

In contrast, the NSE Web site, which only gives its own figures, raised the subscription figure from 670 million shares on Friday to 720 million on Saturday and 820 million on Sunday. The ONGC issue closed on Saturday.

This means the subscriptions on BSE alone have come down drastically from about 497.6 million shares on Friday to around 240 million on Sunday evening, after dipping to 40 million in the morning.

BSE executives attributed this either to cancellation of bids or change in multiple options by all types of bidders.

The sharp fluctuations in the subscription level could be due to "revision of bids during the issue period", a BSE official said. The revision of bids could include increase or reduction in quantity/price, cancellation of bids, or change in multiple options by all types of bidders, the official said.

"We will be not be able to say whether similar changes were effected in the NSE data," the official added. When contacted, an NSE executive said, "We stand by our figures, which are correct. If there is no cancellation, the figures will not decline."

"It is estimated that the multiple options in this data will be about 7.5 million shares," BSE officials said.

Asked why NSE is not giving the consolidated data on ONGC bids, which it is required to do, the NSE executive said: "We do not get the correct figures in time from the other exchange, and hence reconciliation becomes a problem. This is why we only give our data on the Web site. However, for regulatory purposes we put out the cumulative figures on trading terminals every hour so that brokers are able to get the total picture."

The executive also said the exchanges could not net off multiple bid figures. "Only lead managers to the issue can get the right figure after the allotments are made. The exchange has no basis to net off multiple bids," he pointed out.