The benchmark Straits Times Index endured a lacklustre session on Monday, closing a mere 0.87 point up at 3,236.97.
Dealers said traders were unwilling to adopt fresh positions ahead of a news-heavy week, with the United States Federal Reserve policy meeting starting on Tuesday.
Just 1.7 billion shares worth 856.6 million changed hands.
Losers led gainers 261 to 138, with 401 counters unchanged.
Regional markets ended mainly lower, with Japan down 3.32 per cent, Hong Kong 0.54 per cent lower and Shanghai 1.72 per cent behind.