The S&P BSE Sensex and NSE Nifty 50 Indexes erased intraday gains and extended declines to second straight day dragged by selling pressure in banking, financial services and auto sector shares. The 50-share Nifty 50 index ended below important psychological level of 11,100 for the first time since March 8 while the 30-stock BSE benchmark Sensex dropped to lowest level since May 16. Selling pressure in today's session was broad-based as the Nifty Midcap 100, Nifty Smallcap 100 and Nifty 500 Indexes dropped 1 and 2.2 per cent each.