New York, March 12 (DPA) US stock markets gained Friday despite the massive devastation caused by Japan's magnitude 8.9 earthquake, as a dip in oil prices heartened investors.

Still, Japanese companies that trade in New York, such as carmakers Toyota and Honda and technology maker Sony, fell more than two percent.

On Japanese markets, the benchmark Nikkei 225 Stock Average lost 179.95 points, or 1.73 percent, to close at 10,254.43, while the broader Topix index was down 15.33 points, or 1.65 percent, at 915.51.

Concern over oil prices amid unrest in the Arab world has driven the markets for weeks, but oil prices fell Friday and protests in Saudi Arabia were calmer than expected.

Meanwhile, US President Barack Obama reiterated assurances that the US was prepared to use oil stockpiles if necessary and would monitor prices to prevent gouging.

"Should the situation demand it, we are prepared to tap the significant stockpile of oil that we have in the Strategic Petroleum Reserve," Obama said in a press conference.

The blue-chip Dow Jones Industrial Average rose 59.79 points, or 0.5 percent, to 12,044.4. The broader Standard and Poor's 500 Index added 9.17 points, or 0.71 percent, to 1,304.28. The technology-heavy Nasdaq Composite Index gained 14.59 points, or 0.54 percent, to 2,715.61.

The markets were down for the week. The Dow shed 1.03 percent, the S&P lost 1.28 percent and the Nasdaq fell 2.48 percent.

The US currency slid against the euro to 71.92 euro cents from 75.50 euro cents Thursday. The dollar lost ground against the Japanese currency to 81.86 yen from 82.91 yen.