Sensex tanks 555 pts, Nifty below 7650, at 13-month low

The 15 per cent stake will give OVL about 3.5 million metric tonnes of oil a year.

Under the terms of the agreement, OVL will get two seats on the Board of Directors of Vankorneft – a Rosneft subsidiary that operates the Vankor field. Rosneft will retain full control of infrastructure of the Vankor cluster, they said.

9:35 am Acquisition: Cipla is set to buy 100 percent of generic businesses of two pharmaceutical companies in the US for USD 550 million. It is the second landmark acquisition in Cipla’s 80 years of history. "Cipla today announced that its UK arm, Cipla EU has entered into definitive agreements to acquire two US-based companies, InvaGen Pharmaceuticals Inc, and Exelan Pharmaceuticals Inc," said the Mumbai-based pharma company in its filing.9:30 am Views: The European Central Bank (ECB) on surprised markets when its President Mario Draghi downgraded inflation forecast and pledged more quantitative easing (QE) if needed. Micheal Every of Rabobank believes this will have a near-term impact on equities and the markets will rally as long as some central bank or the other continues to pump in money.

He expects the United States non-farm payroll data, which is expected to come out later in the day, to come in at 217,000 in August versus 215,000 In July. He says if the data is strong, then the US Federal Reserve may increase interest rates on September 18.

Also, he adds that if the Fed hikes it rates, there will be further downside to emerging markets (EMs).

9:22 am Market slips: The market has started to slip. The Sensex is down 223.05 points or 09 percent at 25541.73 and the Nifty slips 74.35 points or 0.9 percent at 7748.65. About 284 shares have advanced, 791 shares declined, and 33 shares are unchanged.

Tata Motors, Axis Bank, Tata Steel, BHEL and ICICI Bank are major losers while Cipla is up 2 percent.

Don't miss: ECB's Draghi pledges more QE if needed

The market has once again opened lower. The Sensex is down 146.17 points or 0.6 percent at 25618.61, and the Nifty is down 48.75 points or 0.6 percent at 7774.25. About 229 shares have advanced, 434 shares declined, and 30 shares are unchanged.

Cipla, Infosys, Lupin, Wipro and ONGC are top gainers while M&M, Axis Bank, Vedanta, Dr Reddy's Labs and Tata Steel are major laggards in the Sensex.The Indian rupee gained 9 paise in the early trade. It has opened at 66.15 per dollar against 66.24 a dollar in previous session.NS Venkatesh of IDBI Bank said, "Rupee ended marginally weaker yesterday breaking a 2-day gain. The market today will take cues based on equity market movement as well as expectations from the non-farm payroll data.""European Central Bank's (ECB) action of continuing Quantitative easing (QE) beyond September 2016 has also strengthened the dollar. The range today is seen between 66.15-66.45/dollar," he added.The euro fell more than 1 percent against the dollar after the ECB cut economic growth targets and left interest rates unchanged. The dollar index rose above the 96 mark.Asian stocks are mixed on the final trading day of the week, mirroring the lead from Wall Street overnight. Market volatility was high in early trade as investors awaited the nonfarm payrolls report for August that may play a crucial role in the Federal Reserve's decision about when to lift interest rates. Overnight, major US indexes ended mostly higher. The Nasdaq Composite shed 0.4 percent, while the blue-chip Dow Jones Industrial Average and S&P 500 ticked up 0.1 percent each.