At 10.30am, the Sensex was at 27,817, weaker by 139 points and the Nifty was quoting below its crucial technical level of 8,450 at 8,417, down 39 points. The midcap and smallcap indices had, however, edged higher by 0.2% each at 10,645 and 11,226 respectively.

The benchmark indices had surged more than 2% for the week ended May 22 due to positive global cues and the government's moves to assuage fears on the Minimum Alternate Tax (MAT) front, among other reasons.

The markets are, however, likely to be volatile this week due to the impending F&O expiry on Thurday and the next batch of quarterly results.

On the results front, Canara Bank, Central Bank of India, Transport corporation of India and Bombay Dyeing are likely to announce their results today.

On the global front, the trading activity is likely to be thin in this session as UK and US markets are shut for the Spring Bank Holiday and Memorial Day respectively. The South Korean and Hong Kong markets will also remain shut on Monday.

The rupee fell seven paise to 63.59 against the US dollar in early trade today at the Interbank Foreign Exchange due to rise in the greenback's value against other global currencies. Forex dealers attributed the fall to the dollar's strength on jump in US core inflation and demand for the American currency from importers.

The rupee had gained 12 paise to end at 63.52 against the dollar in the previous session on Friday on sustained selling of the dollar by banks and exporters.

Technical chartists expect a possible immediate correction around 8300 – 8250 levels. The stop loss for this trade set up can be kept at 8570, which may negate the above-mentioned hypothesis, they say.

"The coming week may trade with enhanced volatility on account of May series derivative expiry on the NSE. Thus, traders are advised to trade with a proper exit strategy and avoid taking undue risks," points out a technical analyst with Angel Broking in a morning note.

Canara Bank, Central Bank of India, Transport corporation of India and Bombay Dyeing are likely to announce their results today.

The FMCG sector is having a weak session of trade, while the IT space has build on the gains witnessed in the previous week.

The FMCG index has shed about 1%, with ITC leading the fall. The FMCG major has dipped 2.4% to Rs 320 after reporting a lower-than-expected 3.7% year-on-year (y-o-y) growth in its net profit at Rs 2,361 crore for the fourth quarter ended March 2015 (Q4) due to muted growth in cigarette business and decline in agri segment. Hindustan Unilever, Radico Khaitan, Godrej Consumer Products and Nestle have also shed about 1% each.

In other results impact, Rolta India has slipped 8% to Rs 115 after the company said that its consolidated net profit for the quarter ended March 31, 2015 (Q3) more than halved at Rs 36.01 crore over the previous quarter due to lower operational revenues.

The metal sector is also exhibiting weakness, with Vedanta and Tata Steel shedding about 2% each.

On the other hand, Bharti Airtel, ONGC and M&M have added 1% each. And index heavyweight RIL is trading marginally in the green at Rs 905.

The market breadth is positive. Out of 2,013 stocks traded on the BSE, there are 993 advancing stocks as against 933 declines.