Shares of Oil and Natural Gas Corporation (ONGC) has dipped 3.4% to Rs 397 on National Stock Exchange (NSE) in otherwise firm market, on reports that the government is expected to sell 5% stake in state-owned oil exploration and production company by early next month. In the past two days, the stock declined 5.25% from Rs 419 on October 20, as compared to 1.2% rise in the benchmark index CNX Nifty. Disinvestment Secretary Aradhana Johri met bankers in Mumbai on Monday to discuss the sale which is likely to fetch around Rs 18,000 crore to the government, the Business Standard report suggests. Citigroup and HSBC are among five banks chosen to manage the planned sale of a stake in ONGC, the Reuters report suggests. Currently, the stock is trading 16% lower from its all-time high of Rs 472 touched on June this year.