Global stock markets edged lower while short-dated U.S. Treasury yields held near two-month highs on Monday as investors weighed the possibility that U.S. interest rates could soon rise.

Commodities were mostly lower. Oil prices fell for a fourth session in a row as investors worried about global supply, while gold declined to a 3 1/2-week low.

In the United States, an imminent rise in interest rates was looking more probable. The Federal Reserve will likely tighten policy a bit more quickly in 2017 than this year, by perhaps one or two more rate hikes, San Francisco Fed President John Williams said on Monday.

St. Louis Fed President James Bullard said a relatively tight labor market in the United States may put upward pressure on inflation, boosting the case for higher interest rates.

The Fed surprised investors when the central bank's meeting minutes released last week opened the door to a rate hike as early as in June.

Topping the agenda this week is whether U.S. economic data adds to the likelihood of a June or July rate increase.

MSCI's all-country world stock index was down 0.2 percent while U.S. stocks also ended slightly lower.

"The market needs to be coddled and gently eased into a slightly higher interest-rate environment, and that appears to be what the Fed is doing," said Tim Ghriskey, chief investment officer of Solaris Group in Bedford Hills, New York.

"Rates need to normalize, and the Fed needs to give itself room to lower again in the event of another financial crisis," Ghriskey said.

The Dow Jones Industrial Average closed down 8.01 points, or 0.05 percent, at 17,492.93, the S&P 500 lost 4.28 points, or 0.21 percent, to 2,048.04 and the Nasdaq Composite dropped 3.78 points, or 0.08 percent, to 4,765.78.

The pan-European FTSEurofirst 300 index of leading regional stocks ended down 0.5 percent.

Shares of Monsanto closed up 4.4 percent at $106 after Bayer unveiled a $62 billion bid for U.S. seeds company Monsanto. Bayer AG fell 5.7 percent during the European session.

Short-dated U.S. Treasury yields edged up, with the two-year yield hovering at its highest in two months on Fed rate-hike bets.

The two-year Treasury yield hit 0.905 percent, nearing the two-month peak of 0.920 percent set last Thursday, while benchmark 10-year Treasury notes were up 4/32 in price with a yield of 1.835 percent, down 1 basis point from Friday.

Investors also digested economic data that showed eurozone private-sector growth in manufacturing and services slowing a little in May, even though Germany continued to power ahead.

In currency markets, the U.S. dollar tumbled nearly 1 percent against the yen on Japanese trade data and U.S. resistance to currency intervention by Tokyo.

The dollar was last down 0.9 percent at 109.19 yen, while the dollar index, which measures the greenback against a basket of six major rivals, was last down 0.12 percent at 95.223.

Oil prices slid after Iran vowed to ramp up output and as a slump in the number of rigs drilling for crude in the United States stalled. Brent's front-month fell 37 cents to settle at $48.35 in a fourth straight day of losses, matching a similar streak in mid-April, while U.S. crude fell 33 cents to $48.08 a barrel.

In the metals market, Gold dipped to a 3 1/2-week low on the Fed rate hike expectations, but prices came off their lows as late-day short-covering entered the market. Spot gold was down 0.1 percent at $1,250.96 an ounce after falling earlier to $1,242.63 an ounce, the lowest since April 28.