However, Tata Teleservices (Maharashtra) (up 1.67 per cent), Himachal Futuristic Communications (up 0.60 per cent) and OnMobile Global (up 0.24 per cent) were trading up.
The BSE Telecom index was trading 27 points lower at 1,423 around 11.30 am (IST).
Besides telecom, pharma, FMCG and banking stocks were under selling pressure.
Nifty50, after staying above 10,000-mark for seven straight sessions, slipped below the psychological level to touch 9,988.
The indices were pulled lower mostly by Dr. Reddy’s Laboratories, Sun Pharma, Lupin, Tata Power, Cipla, ONGC and Reliance Industries.
Benchmark Nifty50 index was 16 points down at 9,998, while the 30-share Sensex was 97 points down at 32,141 around 11.30 am (IST).
In the Nifty50 pack, 27 stocks were trading in green, while 24 stocks were in red.