Asian markets saw mixed trading on Wednesday with gains capped on concerns surrounding the future pace of US central bank stimulus.

The Shanghai Composite was trading 0.56% lower or 11.62 points to 2,060.97.

Hong Kong's Hang Seng was trading 0.98% lower or 215.52 points to 21,754.77.

The Japanese Nikkei finished 0.21% higher or 27.95 points to 13,424.33.

Australia's S&P/ASX finished 0.54% higher or 27.60 points to 5,105.80.

South Korea's Kospi finished 1.08% lower or 20.39 points to 1,867.46 points.

Market participants await the minutes from the US Federal Reserve's July policy meeting, expected at 2 pm Eastern time today. They could provide hints about the timing of the planned reduction of monetary stimulus. The Fed's $85bn a month bond-buying program has stimulated the US economy and the markets the world over for a while now.

"Emerging volatility in global bond markets and an exodus of capital in emerging equity markets is a possible precursor for things to come, and is concerning to say the least," said Tim Radford, global analyst at Rivkin Securities.

"Tonight will be crucial in determining whether the theme of bond market volatility will continue, seeing yields possibly surge higher and place added pressure on global market participants."

The Fed's FOMC is due to meet on 17 September, 29 October and 17 December. The September and December meetings will be followed by a news conference led by Fed Chairman Ben Bernanke, where he may signal a tapering of the central bank's massive stimulus programme.

Wall Street also Mixed

On Wall Street, indices ended mixed on 20 August as Fed concerns weighed on investor sentiment.

The Dow finished 7.75 points lower at 15,002.99. The S&P 500 closed 6.29 points higher at 1,652.35, while the Nasdaq ended 24.50 points higher at 3,613.59.

Company Stock Movements

In Tokyo, utility firm Tokyo Electric Power (Tepco) tanked 8.8%.

Tepco, the operator of the crippled Fukushima nuclear power plant, has admitted that about 300 metric tonnes (660,000 pounds) of "highly radioactive water" has leaked from a storage tank. This adds to the contaminated water leaks reported in recent weeks.

A stronger yen pulled down exporters' stocks. Automaker Toyota Motor lost 2% while Fast Retailing was down 1.4%.

Sony shed 0.1%, reversing sharp gains. The company has taken 1 million PlayStation 4 pre-orders the world over and the gaming console will go on sale in the UK on 29 November.

In Hong Kong, real estate firm Hang Lung Properties fell 2.6% while life insurance major AIA Group lost 2.2%

State-owned oil major Cnooc gained 3.6% after it reported a 7.9% increase in profit for the first half of the year. Higher oil and gas output pushed up the company's profit.

In Sydney, resources major BHP Billiton lost 2.3% after it reported a 30% drop in profit for the financial year ended 30 June. Lower commodity prices pulled down the company's profit.

Woodside Petroleum lost 2.3% after it lowered its full-year output forecast. The oil and gas major reported a 7.5% increase in profit for the first six months of the year.

Macquarie Group added 1.5% while rival Commonwealth Bank of Australia moved up 1%.

In Seoul, automaker Kia Motors gained 1.6%. Consumer Report magazine ranked its Cadenza premium sedan in second place in a list of large sedans.