Asian stock markets fall after Chinese manufacturing activity weakened in January

Asian stock markets were mostly lower Monday after Chinese manufacturing weakened and oil went on roller-coaster ride.

KEEPING SCORE: The Shanghai Composite Index gave up 1.2 percent to 3,173.08 and Tokyo's Nikkei 225 was off 0.6 percent to 17,576. Hong Kong's Hang Seng shed 0.3 percent to 24,441.32. Seoul's Kospi was down 0.1 percent at 1,947.68. Markets were mixed in Southeast Asia while Australia's S&P/ASX 200 rose 0.8 percent to 5,631.50.

CHINESE MANUFACTURING: Surveys by HSBC Corp. and a Chinese industry group found manufacturing activity in the world's second-largest economy weakened in January. The China Federation of Logistics and Purchasing said its purchasing managers' index fell to a 28-month low. A separate index by HSBC edged up but still showed activity contracting. Both blamed weak demand in China and abroad. Analysts said they expect this to prompt Beijing to inject more credit into the economy or launch other stimulus measures.

THE QUOTE: "We think demand in the manufacturing sector remains weak and more aggressive monetary and fiscal easing measures will be needed to prevent another sharp slowdown in growth," said HSBC economist Hongbin Qu in a report.

OIL ROLLER COASTER: The price of U.S. and international benchmark crudes slid after jumping Friday on signs American production is slowing following big price drops since last June. The price of oil plummeted about 60 percent since June as global supplies grew faster than demand. OPEC has declined to cut back on its production, putting pressure on U.S. companies to curtail drilling as oil prices fall to a level that makes some production unprofitable. U.S. benchmark crude was down $1.18 to $47.06 per barrel on the New York Mercantile Exchange. The contract surged by an unusually large margin of $3.71 on Friday, or about 7 percent, to close at $48.24. Brent crude, used to price international oils, shed $1.35 to $51.64 a barrel in London after rising by $3.86 on Friday.

DOLLAR WORRIES: Concern the strong dollar will dampen U.S. exports and corporate profits have weighed on stocks. Weaker revenue from foreign markets would offset gains from lower oil prices. Those concerns intensified Friday after Russia's central bank unexpectedly cut interest rates, sending the ruble down sharply against the dollar.

WALL STREET: The U.S. stock market capped a rough month Friday, delivering its third loss in five days and extending its declines for the year. The Dow Jones industrial average dropped 251.90 points, or 1.5 percent, to close at 17,164.95. The S&P 500 index lost 26.26 points, or 1.3 percent, to 1,994.99. The Nasdaq composite fell 48.17 points, or 1 percent, to 4,635.24.

CURRENCIES: The dollar gained to 117.77 yen from Friday's 117.43 yen. The euro strengthened to $1.1310 from $1.1285.