Oil prices hit 6-1/2-year lows on Monday on concerns over the global oil oversupply and on worries over the global slowdown. The Japanese Nikkei stock index fell almost 4%, while China's Shanghai Composite declined more than 8%. European and U.S. sticks are also trading lower.

Concerns over a slowdown in the Chinese economy weighed on markets.

China allowed pension funds to invest in domestic stocks. Pension funds are now able to invest up to 30% of their net assets in domestic stocks.

China hopes with this decision to boost the liquidity on the stock market and to stop a massive selloff.

According to the newspaper the Financial News, the People's Bank of China (PBoC) plans to use a mix of innovative monetary policy tools to inject liquidity into the financial system. The central bank wants to make "flexible use" of the new tools.

The new tools should replace foreign-exchange purchases.

The oil driller Baker Hughes reported that the number of active U.S. rigs rose by 2 rigs to 674 last week. It was the fifth consecutive increase.

Combined oil and gas rigs remained unchanged at 884.

WTI crude oil for October delivery declined to $38.61 a barrel on the New York Mercantile Exchange.

Brent crude oil for October decreased to $43.10 a barrel on ICE Futures Europe.