Mumbai, May 11 -- The headline equity indices tumbled sharply on Monday, extending losses for a third consecutive session. Investor sentiment weakened after U.S. President Donald Trump rejected Iran's response to a U.S. peace proposal, fuelling fears of a prolonged and destabilising conflict in the Persian Gulf. Brent crude surged above $100 a barrel, while the rupee slid close to the 95-per-dollar level. Domestic sentiment also remained under pressure after Prime Minister Narendra Modi urged citizens to conserve fuel and curb non-essential imports such as gold. The Nifty slipped below the 23,850 mark, dragged down by steep losses in consumer durables and PSU bank stocks. However, healthcare and pharma shares bucked the broader selloff an...