Total trading value was 64.97 billion baht, with 15.77 billion shares changed hands.
The SET50 index declined 2.88 points or 0.28% to 1,030.19 in trade worth 35.87 billion baht.
The MAI index bucked the trend, increasing 7.06 points or 1.30% to 548.72 points, with total transaction value of 4.43 billion baht.
Retail and foreign investors, as well as brokers were net buyers of 2.51 billion, 796.94 million and 723.47 million baht respectively while local institutions sold a net 4.04 billion baht.
The main gauge took a hit in line with regional markets after a Malaysian Airlines plane was shot down in Ukraine last night.
Telecommunications stocks were also hit by the National Council for Peace and Order's decision to put off the 4G frequency auction by one year.
But large property, energy and transport stocks such as Airports of Thailand (AOT) saved the day, bringing the main index from the low of 1,523.53 points at 11.30am in the afternoon session.
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