Asian stock markets turned in a mixed performance Monday, with Seoul retreating on another chip-sector rout, while signals from Beijing helped undergird China-exposed exchanges.

Hong Kong and Shanghai finished in the green, but Tokyo trading floors were closed for holiday. Seoul's semiconductor-heavy KOSPI index fell 4.5%, although other regional exchanges were muted.

In Hong Kong, the Hang Seng Index opened higher and held ground, finishing up 2.4% after assurances from Beijing that government regulators and state investment funds will take steps to preserve equity values.

The broad gauge Hang Seng rose 580.81 to 25,143.05, as gaining issues outnumbered losers 86 to five. The Hang Seng TECH Index gained 2.8% on the day, while the Mainland Properties Index rose 0.9%.

Leading the upside was state-controlled oil producer CNOOC, gaining 5.2%, while utility holding company Power Assets declined 1.7%.

On the mainland, the Shanghai Composite rose 0.9% to 3,796.28.

In economic news, the People's Bank of China left one-year and five-year prime loan rates unchanged at 3% and 3.5% respectively.

In market news, the China Securities Regulatory Commission (CSRC) will prevent risks in the capital market, boost supervision, and safeguard fair market order, commission chairman Wu Qing said at an investor meeting, reported Radio Television Hong Kong.

Media reports that state investment pools could buy equities to stabilize markets also boosted trader sentiments.

On the other regional exchanges, the Taiwan TWSE declined 0.5%; the Australian ASX 200 declined 0.1%; the Singapore Straits Times Index fell 0.2%, and the Thai Set rose 0.4%. In late trading in Mumbai, the Sensex was down 0.6%.

The MSCI All Country Asia Pacific Index fell 0.2% on the day.