At 12.30pm, the benchmark index was down 9.2 points to 1,534.41.
Bank counters were seen shedding weight with Maybank falling five sen to RM8.25, Public Bank down one sen to RM4.14, Hong Leong Bank dropping 14 sen to RM5.64 and CIMB unchanged at RM5.41.
Other laggards included IHH sliding eight sen to RM6.70, Petronas Gas shedding four sen to RM17.18 and IOI falling seven sen to RM3.72.
On thee broader market, trading activity was muted given the holiday season with 1.36 billion shares traded for RM643.67mil.
Top actives were XOX up 0.5 sen to 3.5 sen, SMTrack gaining 1.5 sen to 19 sen and AT Systemization rising 0.5 sen to 3.5 sen.
Meanwhile, Asian markets were subdued by the spread of Omicron as investors repositioned their portfolios for the new year.
China's composite index rose 0.4%, Hong Kong's Hang Seng added 1.2% while Australia's ASX200 dropped 0.9%.
Japan's and South Korea's markets were closed as they ended trading for 2021 yesterday.