At 12.30pm, the key index was down 11.27 points to 1,605.46. The market breadth had turned negative with 723 decliners versus 300 gainers.
Investors had taken a step back from the recovery-themed rally on Bursa Malaysia amid political developments and as some were cautious that the rally had been overdone.
Maybank was down four sen to RM8.29, Public Bank slid one sen to RM4.21 and Hong Leong Bank fell six sen to RM19.02.
Other laggards included Petronas Chemicals down 11 sen to RM8.09, Hartalega sliding seven sen to RM9.63 and Petronas Gas shedding 20 sen to RM15.54.
Actives included Berjaya up 5.5 sen to 28 sen, Widad up eight sne to 51.5 sen and Dynacia down two sen to 12.5 sen.
In Asia, markets were dragged lower by a retreat in Chinese stocks following a recent rally.
Japan's Nikkei dropped 0.1% and South Korea's Kopsi shed 0.6%.
In China, the composite index fell 1.4% while Hong Kong's Hang Seng slid 1.5%.
Australia's ASX@00 was down 0.1%.