Riyadh: Shares in Saudi Arabia rose the most in six weeks after US stocks advanced for a second straight week on the Federal Reserve’s plan to buy mortgage securities and on higher oil prices.

Saudi Basic Industries Corp, the world’s largest petrochemical maker known as Sabic, rose to the highest level since May 30. National Industrialization Co., an industrial and manufacturing firm, climbed the most in a week. Samba Financial Group, the kingdom’s second-biggest bank by market value, advanced the most in almost two weeks.

The Tadawul All Share Index gained 0.9 per cent to 7,169.73 in Riyadh at 11:33am. The Arab world’s biggest stock market has increased 12 per cent this year.

The US “stimulus will be a factor domestically as the S&P 500 reached near five-year highs,” Asim Bukhtiar, head of research at Riyad Capital, said in response to emailed questions. “We expect positive opening this morning on the heels of strong gains in developed markets over the past two days. Petrochemicals should benefit from $99 crude.”

Equities rallied as the Fed said on September 13 that it will expand its holdings of long-term securities with open-ended purchases of $40 billion of mortgage debt a month in a third round of quantitative easing as it seeks to boost growth and reduce unemployment. The Standard & Poor’s 500 Index added 1.9 per cent this week to 1,465.77, extending its two-week rally to 4.2 per cent. The index is 6.8 per cent away from its all-time high set in October 2007.

Oil climbed to the highest level in more than four months as the Fed’s plan boosted demand for commodities and stocks. Crude oil for October delivery advanced yesterday 69 cents, or 0.7 per cent, to $99 a barrel on the New York Mercantile Exchange, the highest settlement since May 3. Futures touched $100.42 in intraday trading. Prices increased 2.7 per cent this week and are up 11 per cent from a year ago.

Sabic gained 2.4 per cent to 94.75 riyals, while National Industrialization increased 1.5 per cent to 33.1 riyals. Samba added 1.3 per cent to 47.6 riyals.

Saudi Arabia’s stock exchange is the only Gulf bourse operating on Saturdays.