Shares of capital goods, power, realty, banking, consumer durables and auto sectors fell on heavy selling pressure. (Agencies)
On the macro front, the government will announce data on inflation based on the wholesale price index (WPI) for May on Monday.
Geopolitical concerns shifted from the crisis in Ukraine to the worsening situation in Iraq. US President Barack Obama has said he will consider over the next several days options to help Iraqi forces turn back militants sweeping across the country. The insurgency highlights the risks to the world's oil supply.
The Sensex resumed slightly higher at 25,239.50 and moved in a range of 25,268.41 and 25,076.28 before quoting at 25,132.87 at 1000 hrs, showing a loss of 104.30 points, or 0.41 percent, from its last weekend's level.
The 50-share CNX Nifty also dropped 53.60 points, or 0.71 percent, to 7,488.50 at 1000 hrs.
Major losers were Tata Power (3.04 percent), Larsen (2.41 percent), Coal India (2.20 percent), M&M (2.16 percent), BHEL (2.06 percent), Axis Bank (1.82 percent), ONGC (1.69 percent), Tata Steel (1.64 percent) and SBI (1.53 percent).
Asian stocks also edged lower in early trade amid an escalation of violence in Iraq. Key benchmark indices in Taiwan, Hong Kong, Japan and South Korea fell 0.01-0.62 percent while indices in China and Singapore rose 0.04-0.11 percent.
Meanwhile, foreign portfolio investors (FPIs) bought shares worth a net Rs 1,099.92 crore last Friday, as per the provisional data from the stock exchanges.
Shares of capital goods, power, realty, banking, consumer durables and auto sectors fell on heavy selling pressure.