The key indices of the Indian equity markets traded on a flat note with marginal losses during the mid-afternoon session on Tuesday. The barometer 30-scrip Sensitive Index (Sensex) crossed the 34,000-level for the first time and scaled a fresh high of 34,005.37 points on an intra-day basis, surpassing it's Friday's (December 22) intra-day high of 33,964.28 points.