At 12.30pm, the index was 1.9 points lower at 1,595.81 points.
While regional markets were mostly higher on the back of US data that showed inflation levels remained at reasonable levels, investors on Bursa Malaysia were cautious over the rising Covid-19 cases in the recent days, which outpaced the rate of patient recovery.
Finanicial counters slid with Hong Leong Bank falling 16 sen to RM18.06, Public Bank dropping three sen to RM4.20 and Maybank sliding one sen to RM8.31. CIMB added three sen to RM4.26.
Meanwhile, telcos continued to descend from recent highs as investors took cash out of the Axiata, down two sen to RM3.85, and Digi, losing four sen to RM4.29.
Glove makers were mixed with Top Glove gaining four sen to RM5.12, Supermax adding four sen to RM4.50 and Hartalega slipping five sen to RM9.41.
On the broader market, Dataprep surged 29.5 sen to RM1.05, Vitrox up 18 sen to RM15.88 and Gopeng climbing 14 sen to 97 sen.
Top actives were Minda down on sen to 16.5 sen, Lambo up 0.5 sen to 2.5 sen and Dagang Nexchange rising 0.5 sen to 82.5 sen.
In China, the composite index was up 0.15% and Hong Kong's Hang Seng gained 1.25%.
South Korea's Kospi rose 0.2% and Australia's ASX200 rose 0.55%.
Japan's Nikkei bucked the trend, losing 0.4%.