* Light physical buying seen in Asia, supporting prices
* Platinum, palladium firm on equity strength, S.Africa power concerns
* Coming up: Greece's parliament votes on aid package (Adds comments, details; updates prices)
By Rujun Shen
SINGAPORE, June 29 (Reuters) - Gold edged higher on Wednesday, as investors are optimistic that Greece's parliament will approve an austerity plan later in the day, likely to help underpin sentiment in bullion and other commodities.
Light physical buying in Asia also helped support prices, although the limited volume was seen as insufficient to push gold out of its trading range, dealers said.
Greece remains in focus, as its parliament is scheduled to vote on an austerity package demanded by international lenders as part of a massive bailout later on Wednesday.
"There are still reasons to buy gold, but just not any new reason for now," said Yingxi Yu, an analyst at Barclays Capital.
"Market participants are generally positive on gold, but it is a question whether now is the right time to enter the market given the volatility in risky assets such as equities and oil in particular."
The 19-commodity Reuters-Jefferies CRB index rose 1.7 percent on Tuesday, its biggest daily rise in nearly six weeks, as investors bet that Greece will approve the austerity plan and avoid defaulting its debt.
Spot gold inched up 0.2 percent to $1,502.70 an ounce
by 0336 GMT, building on gains from the previous session. COMEX
gold
Gold has been trading around $1,500 in the past few sessions, with bargain hunters waiting to buy below that level, while sluggish seasonal demand caps upside potential.
"People are not keen to go short, but we don't see a rush to buy gold either because it is the low season," said a Singapore-based dealer.
In the long term, the outlook for gold prices remain intact, as low interest rates in the United States, uncertainties in euro zone's fiscal situation, and high inflation in major emerging economies are likely to help gold retain its appeal.
Platinum group metals gained for the second session, following strength in global equities, which were lifted by optimism on the Greek vote outcome.
Concerns on power supply in South Africa, the world's top producer of the metals, also supported market sentiment.
The National Union of Mineworkers in South Africa on Tuesday called its members for a strike at power firm Eskom, which supplies 95 percent of the country's power.
Spot platinum gained 0.9 percent to $1,704, up from a three-month low of $1,661.24 hit earlier in the week.
Spot palladium rose 0.7 percent to $741.49.
Platinum and palladium have wide industrial applications, and are key ingredients in autocatalysts.
Precious metals prices 0336 GMT Metal Last Change Pct chg YTD pct chg Volume Spot Gold 1502.70 2.20 +0.15 5.86 Spot Silver 34.02 0.15 +0.44 10.24 Spot Platinum 1704.00 14.80 +0.88 -3.59 Spot Palladium 741.49 5.09 +0.69 -7.26 TOCOM Gold 3925.00 28.00 +0.72 5.26 36832 TOCOM Platinum 4504.00 70.00 +1.58 -4.09 11110 TOCOM Silver 88.80 1.20 +1.37 9.63 1550 TOCOM Palladium 1955.00 62.00 +3.28 -6.77 455 COMEX GOLD AUG1 1503.60 3.40 +0.23 5.78 4220 COMEX SILVER JUL1 34.09 0.45 +1.34 10.18 1179 Euro/Dollar 1.4350 Dollar/Yen 81.02 TOCOM prices in yen per gram. Spot prices in $ per ounce. COMEX gold and silver contracts show the most active months (Editing by Ed Lane)