By Sanjeev Srivastava in Bombay

It was a heady week on the Bombay stock exchange with the BSE sensex gaining a whopping 620 points or nearly 11% in the last five trading sessions to close at 5933.5 points on Friday - tantalisingly close to the magical 6,000 mark.

The bull run may, however, be spoiled by additional margins imposed on the top 25 Indian brokerage firms by the Indian market regulator, Securities and Exchange Board of India (Sebi).

The Sebi directive , which came after close of trade on Friday evening, means that these brokerage firms will no longer be allowed to increase their exposure in the market by providing additional bank guarantee - as is the procedure now - but would have to either cough up the additional money in the form of cash upfront or give fixed bank deposits as security.

According to Sebi, the decision was taken to check excess volatility in the markets and will be reviewed after four weeks.

Market observers say the decision could force speculators to cut their positions and result in a correction in the market.

But that could happen only on Monday.

Tech shares high

The star of the week was once again the software sector.

Shares of Infosys, Wipro, Satyam Computers touched their all time highs on the Indian markets.

The rupees five paid-up share of Infosys finished less than 50 Rupees short of the magical 10,000 mark on Friday while the two rupees paid-up share of Wipro closed above the 6,000 level.

The Infosys ADR (two ADRs make a share) on Nasdaq also gained nearly $200 this week and was quoting $50 up in early Friday trading on the Nasdaq.

According to market sources, the interest in Infosys is being driven by rumours of a possible acquisition or strategic alliance with Cambridge Technologies of US.

Telecom outperforms

Telecom sector stocks also continued to outperform other sectors in the Indian market and shares of public sector telecom companies like VSNL and MTNL rose nearly 20%t this week.

Indian companies like the BSES and Mahindra & Mahindra also did well on the back of reports that these companies would shortly have an e-commerce and internet play.

Share prices of a cigarette major - ITC - also surged by more than 20% this week following reports that the company would shortly start an e-commerce venture with a British company.

Another reason for continuing bullishness in the Indian markets is the expectation of a tough budget later this month.

Market analysts are of the opinion that the government may withdraw some populist subsidies and broaden the tax-base in the forthcoming budget in a bid to cut fiscal deficit.