GLOBAL MARKETS-Asia stocks wobble as investors nervously await Fed, BOJ

* Spreadbetters see softer opening for European bourses

* Choppy session on Wall Street offers few directional cues

* Fed, BOJ begin two-day policy meetings on Tuesday

* Yen edges up on speculation BOJ could disappoint

By Lisa Twaronite

TOKYO, Sept 20 (Reuters) - Asian shares edged lower on Tuesday as investors nervously awaited the outcomes of Federal Reserve and Bank of Japan policy meetings that will both conclude on Wednesday.

"The market is more nervous about the BOJ than the Fed as it may give the market a surprise," said Yutaka Miura, a senior technical analyst at Mizuho Securities.

Financial spreadbetters predicted the uneasy mood would extend into European markets

"Today's European open is likely to see a slightly softer open after yesterday's paring back of oil prices from their intraday highs," wrote Michael Hewson, chief market analyst at CMC Markets (LSE: CMCX.L - news) in London, who expected Britain's FTSE 100, Germany's DAX and France's CAC 40 to all open modestly down.

Oil had rallied on Monday before settling off its highs on scepticism over Venezuela's bid to talk up a potential OPEC output freeze, and on indications U.S. crude stockpiles had risen last week.

Brent crude fell 0.4 percent to $45.79 per barrel, while U.S. crude slipped 0.6 percent to $43.05.

EMini futures for the S&P 500 edged up 0.2 percent, after major U.S. indexes ended Monday's choppy session nearly flat.

Global markets have been blowing hot and cold in recent weeks over the Fed's intentions, which remain far from clarified after both hawkish and dovish comments from several Fed officials.

The consensus is that the Fed will leave interest rates unchanged at the end of its two-day meeting on Wednesday, with investors focusing on the statement as well as Chair Janet Yellen's speech for clues on the timing of the central bank's next interest rate increase.

"It's a lot of uncertainty, leading into the Fed," said Jennifer Vail, head of fixed income research at U.S. Bank Wealth Management in Portland, Oregon.

While Vail, like most strategists and investors, expects the Fed to refrain from taking any new steps, she said its statement could include language that's been missing from its recent assessments, such as whether economic risks were "balanced" or "close to balanced."

MSCI (Frankfurt: 3HM.F - news) 's broadest index of Asia-Pacific shares outside Japan slipped 0.1 percent.

Australian shares finished slightly higher. The Australian Securities Exchange opened without incident on Tuesday after technical faults caused extensive disruptions on Monday.

Japan's Nikkei stock index erased earlier gains and shed 0.2 percent, as trading resumed after a public holiday on Monday. Tokyo markets will be closed for another holiday on Thursday, with the highly-anticipated BOJ meeting sandwiched in between the market closures.

The BOJ could make negative interest rates the primary focus of its monetary policy at the conclusion of its meeting on Wednesday, when it conducts what it described as a "comprehensive" assessment of its policies.

Sources have said BOJ policymakers may consider deepening negative interest rates to show determination to maintain an ultra-easy policy bias. The BOJ unveiled its controversial policy in late January.

Rising speculation that the BOJ will stop short of the dramatic action needed to weaken its currency helped send the dollar to a six-day low against the yen of 101.56 yen on Monday. The dollar was last down 0.1 percent at 101.80 yen.

Wary of a flattening Japanese government bond (JGB) yield curve, the BOJ also could seek ways to steepen the curve, such as making its bond buying more flexible.

Policymakers got a taste last week of how markets might react when investors dumped longer-dated bonds on fears the BOJ would slow its purchasing pace.

"The BOJ will likely be the first (among the US and Europe) to push the boundaries of unorthodox monetary policy, having to balance a challenging macro environment with the negative impact of flat curves and negative yields on the financial sector and on the pension system," said Andrea Iannelli, investment director for fixed income at Fidelity International.

The euro was also steady at $1.1173, remaining well above Monday's nearly two-week low of $1.1149.

The dollar index, which tracks the greenback against a basket of six major rivals, was slightly higher at 95.868 , though it was shy of Friday's two-week high of 96.108.

Spot gold added 0.2 percent to $1,315.90 an ounce, on expectations that the Fed will stand pat on rates.

(Additional reporting by Ayai Tomisawa in Tokyo and Nichola Saminather in Singapore; Editing by Kim Coghill and Simon Cameron-Moore)