The Straits Times Index (STI) was up 2.15 points at 3,097.47. The total value of shares traded in the morning session was S$758.5 million, down from S$735.4 million on Wednesday.

"There's nothing much to cheer about in the market and there're too many unknowns. Investors are staying on the sidelines, waiting to see what's next," said Roger Tan, vice president at SIAS Research.

"With the advent of the Middle East and Japan nuclear problems, a lot more factors contributing to uncertainties have been added."

Traders said they expected the STI to consolidate in 3,080-3,100 band in the afternoon, as investors await further cues from the release of US unemployment data on Friday.

Global Logistic Properties (GLP) outperformed the broader index to rise as much as two percent on bargain hunting, following the steep drop in its shares after the Japan earthquake.

However, Daiwa highlighted in a report that GLP's management believes the expected public works and reconstruction activity in Japan after would be positive for its business.

"It's a big company with a lot of good backers. Going ahead, it definitely has a positive development...So far there's no signs of major disruption to their strategy," said Tan.

Shares of Singapore semiconductor firm Serial System jumped as much as 10 percent on expectations it may receive more orders following disruptions at some of its competitors in the aftermath of the Japan earthquake.

At the midday, Serial System shares were up 3.33 percent at S$0.155 while larger rival UMS Holdings saw its shares gain 0.83 percent.

Silicon wafers used to make microchips could temporarily run short over the next few weeks after suppliers halted production after the quake.