Mumbai, Dec. 23 -- The domestic equity markets opened on a flat-to-positive note on Tuesday but soon slipped into negative territory, as hopes of a Santa rally remained muted so far.

Benchmark indices started the session with marginal gains, tracking positive global cues, but selling pressure across the broader market weighed on sentiment.

The Nifty 50 index opened at 26,246.15, gaining 32.80 points or 0.13 per cent, while the BSE Sensex began trade at 85,690.10, up 122.62 points or 0.14 per cent. However, the early optimism faded quickly, with markets turning red as the session progressed.

Market participants noted that although Indian equities opened higher, sustained buying support was missing. Broader market indices on the NSE were...