(Adds close of U.S. markets)
* U.S. bond yields rise on supply, stock gains
* Turkish lira bounces after Monday drubbing, but still shaky
* Oil prices gain on Iran sanctions, supply signals
By Herbert Lash and Laila Kearney
NEW YORK, Aug 7 (Reuters) - Equity markets around the world neared a six-month high on Tuesday, buoyed by a rebound in Chinese stocks and an earnings-driven surge on Wall Street, while oil prices rose on concerns U.S. sanctions against Iran could cause supply shortages.
The equity gains prompted investors to sell safe-haven assets before the first leg of this week's $78 billion quarterly U.S. government refunding, pushing Treasury yields higher.
The dollar weakened against the euro on a more stable Chinese yuan after the currency pair neared but failed to break through technical levels supporting the single currency.
U.S. corporate revenues are growing at a time the European and Japanese central banks continue to prop up their economies, which is suppressing shorter-term interest rates, said Michael Kelly, global head of multi-asset at PineBridge Investments.
"Profits are incredible, actually, and it's not just tax-cut sugar highs," Kelly said.
Of the 428 companies in the S&P 500 that have released second-quarter earnings so far, 79 percent reported above analyst expectations, a beat rate that if it holds will be the highest since Thomson Reuters started reporting the figure in 1994.
Earnings per share without the tax change would be 15.5 percent higher, leading to upward revisions for the rest of the year, according to Credit Suisse.
MSCI's all-country world index of stock markets in 47 countries gained 0.46 percent, while the pan-European FTSEurofirst 300 index of leading regional shares closed up 0.54 percent.
On Wall Street, the Dow Jones Industrial Average closed up 126.73 points, or 0.5 percent, to 25,628.91. The S&P 500 gained 8.05 points, or 0.28 percent, to 2,858.45 and the Nasdaq Composite added 23.99 points, or 0.31 percent, to 7,883.66.
Powered by gains in technology stocks and strong second-quarter U.S. earnings, the benchmark S&P 500 was half a percentage point from its record peak in January.
Tesla Inc shares jumped almost 11 percent after Chief Executive Elon Musk said on Twitter he is considering taking the electric car maker private at $420 per share.
Shares traded as high as $387.46 before closing at $379.57.
Such a deal, at about $72 billion, would take Tesla out of the glare of Wall Street but might limit its access to capital.
Chinese stocks rebounded overnight on hopes of fresh government spending, following a four-day selloff that had knocked them down about 6 percent.
China's central bank on Friday raised the cost of shorting the yuan, which stabilized the currency and helped boost the euro against the dollar.
The dollar index fell 0.19 percent, with the euro up 0.38 percent to $1.1597. The Japanese yen firmed 0.02 percent versus the greenback at 111.41 per dollar.
Turkey's lira recovered as much as 2 percent from Monday's losses of more than 5 percent after Washington moved to end duty-free access to U.S. markets for some Turkish exports.
Benchmark 10-year notes fell 11/32 in price to yield 2.9786 percent, up from 2.938 percent late on Monday.
U.S. gold futures for December delivery settled up 60 cents, or 0.1 percent, at $1,218.30 an ounce.
Crude prices climbed as the United States revived sanctions against Iran. U.S. crude rose 16 cents to settle at $69.17 a barrel and Brent gained 90 cents to settle at $74.65.
The first round of U.S. sanctions target Iran's dollar purchases, metals trading, coal, industrial software and its auto sector.
Additional reporting by Marc Jones, Ahmad Ghaddar and Helen Reid in London, Amy Caren Daniel, Richard Leong in New York; Editing by Meredith Mazzilli and Lisa Shumaker