* Asian stocks struggle to extend gains, still ahead for week
* Fed cheer gives way to caution ahead of Chinese data on Monday
* Selloff in dollar eases, currencies steadier after wild ride
By Ian Chua
SYDNEY, July 12 (Reuters) - Investors in Asian stocks turned cautious on Friday even after a record close on Wall Street, and a decline in the dollar paused as markets braced for Chinese data that could offer telling evidence of weakness in the world's second biggest economy.
Economists polled by Reuters see China's second-quarter GDP growth at a median 7.5 percent. The data is set to be released on Monday.
Foreshadowing an even slower growth rate, China's finance minister said he expected a 7 percent pace for this year, which would be below the government's own official forecast.
"China's weak foreign trade data for June provide a pessimistic edge to second quarter GDP estimates. Monthly data, including industrial production and fixed investment, show China's economy slowed further in the second quarter," said Alaistair Chan, an economist at Moody's analytics in Sydney.
"This year is shaping up to be the slowest since 1999, and the risk is increasing that full-year GDP growth will come in below the government's 7.5 percent target."
Confirmation of any further weakness in China's economy would dampen risk appetite.
Yet China's main markets were still on track for their best week in five months, helped by tentative signs of support for sectors plagued by overcapacity.
MSCI's broadest index of Asia-Pacific shares outside Japan was essentially flat on Friday. Yet after three straight sessions of solid gains, it was on track to end up more than 3 percent for the week, its best since September.
Tokyo's Nikkei added 0.2 percent, South Korea's KOSPI eased 0.7 percent, Hong Kong's Hang Seng slipped 0.5 percent and China's mainland shares shed 0.8 percent.
Bucking the region's weaker trend, Australia's ASX 200 index added 0.4 percent, thanks mostly to strength in the major miners such as BHP Billiton.
European shares were expected to gain at the opening on Friday after Wall Street set record highs.
Capital Spreads forecast Britain's FTSE 100 to open up 0.1 percent, Germany's DAX to rise 0.3 percent, and France's CAC 40 to gain 0.1 percent.
The generally subdued performance on Asian exchanges followed a powerful rise on Thursday and a record closing high for the U.S. S&P 500 index and Dow Jones.
Investors had cheered Federal Reserve Chairman Ben Bernanke's commitment to keep monetary policy accommodative for the foreseeable future.
Before his comments, markets had started to price in the prospect of the Fed scaling back its bond-buying programme as early as September following a string of encouraging data that showed a clear recovery in the economy.
Currency markets were steadier following a breathtaking selloff in the dollar on Thursday as investors cut bullish positions on Bernanke's pledge.
The dollar index, which tracks the greenback's performance against a basket of major currencies, wallowed at 2-1/2 week lows, having slumped more than 2 percent. That fall was the steepest in four years, normally seen only during financial crises.
The euro had set up camp at $1.3082 having jumped as far as $1.3208 on Thursday to be well off this week's trough of $1.2755.
Analysts at BNP Paribas said the fall in the dollar should be seen as an opportunity to buy because they still expect the Fed to begin winding down its stimulus later this year.
"We forecast an acceleration of U.S. GDP growth in Q3 and Q4 that is consistent with the Fed starting its tapering process in the second half of 2013," Steven Saywell wrote in a report.
"We choose to recommend a short GBP/USD at 1.5130, targeting a move to 1.45 with a stop at 1.5310," said Saywell, adding he believed the Bank of England would ease policy in August.
Caution ahead of the Chinese data saw commodity currencies such as the Australian dollar give back much of the recent gains made against the greenback.
The Aussie slipped to $0.9173 from Thursday's high of $0.9306, keeping in sight a 34-month trough of $0.9036 set earlier this month.
The Aussie's decline came even as commodity markets were bolstered by Bernanke's commitment to keep policy loose. Copper was a touch softer on the day at $6,980 a tonne, having jumped 2.6 percent, while gold stood at $1,282 an ounce after a 1.7 percent rally.
Oil lost a bit of momentum as traders took profits on a three-week rally that lifted prices to 15-month highs. U.S. crude eased back to around $104.82 a barrel, having reached $107.45.