Singapore's main index fell at midday, snapping two straight sessions of gains, on profit booking and concerns over Spain's banking sector and that country's soaring bond yields.

Spain's 10-year bond yield on Tuesday rose to 6.86 percent, surpassing peaks seen in November last year to mark its highest since the 1999 launch of the euro.

At 0445 GMT, the benchmark Straits Times Index was down 0.4 percent at 2,784.90, recovering from an intraday low of 2,776.02.

Singapore shares underperformed other Asian bourses, as traders said investors were booking profits after its outperformance on Tuesday, when it rose 0.3 percent against the MSCI Asia-Pacific Ex Japan's 0.3 percent loss.

" Singapore rebounded quite nicely yesterday. So today, what we're seeing is probably some profit-taking because the outlook is still very short-term," said Carey Wong, an investment analyst at OCBC Investment Research.

He added that investors are likely to stay cautious ahead of the Greek elections on June 17.

Property developer CapitaLand Ltd was one of the biggest losers on the index, falling 1.8 percent, while Singapore Exchange dropped 1.3 percent.

1224 (0424 GMT) (Reporting by Leonard How in Singapore; leonard.how@thomsonreuters.com)