G20 finance ministers meet in Turkey as China casts clouds over growth

* Finance chiefs to meet on Friday and Saturday

* IMF has warned of risks posed by China slowdown

* Turkey keen to shake off perception G20 is 'talking shop'

By David Dolan and Asli Kandemir

ANKARA, Sept 3 (Reuters) - When the Group of 20 finance ministers and central bankers meet on Friday in Turkey, China's market turmoil is likely to be the biggest problem they don't do anything about.

Slower growth in China and rising market volatility have boosted the risks to the global economy, staff of the International Monetary Fund warned on Wednesday, describing a mix of potential dangers such as depreciating emerging market currencies and tumbling commodity prices.

But the G20 is unlikely to come up with any concrete measures designed to address the spill-over from the turmoil in the world's second-largest economy, or to call on Beijing to address structural issues such as rising bad debts.

Such lack of action could reinforce the perception among critics that the G20 meetings are little more than a "talking shop" and a photo opportunity for policymakers, an impression Turkey - which holds the G20 presidency this year - has been keen to shake off.

Japanese Finance Minister Taro Aso said this week that it would be beneficial to have a "frank debate" at the G20 on what is happening in the Chinese economy, including a discussion on its structural problems.

But analysts say investors shouldn't hope for too much from the final communique expected to be released near the close of the gathering on Saturday.

"Our expectation is that the communique will 'welcome moves toward exchange rate flexibility in the context of broad economic and financial market liberalisation' or some similar language that each G20 country can interpret as it wants," Citigroup (NYSE: C - news) said in a note.

"It (Other OTC: ITGL - news) also seems very likely that there will be some comfort message on underlying robustness of global economies and commitment to coordinate policies to avoid disruption."

Turkish President Tayyip Erdogan said on Thursday he had asked G20 member states to prepare investment strategies to secure robust, balanced and sustainable global growth.

He said investing in infrastructure was key to securing such growth and that it was important to consider Islamic financing instruments as part of those plans.

'CHINA TRAIN'

"We are all staring down the headlights of the China train these days," said Timothy Ash, a credit strategist at Nomura, adding that for emerging markets there was a need to "get back to basics" of prudential macro policy and structural reform.

Surprising markets, China last month devalued the yuan currency by nearly 2 percent. Beijing has billed the move as a free-market reform measure, and denies allegations that it has started a round of competitive currency devaluations between governments to help exporters.

Officials in Washington, which has long pressed Beijing to move toward a more market-determined exchange rate, greeted the shift with some scepticism and indicated they would watch to make sure it was not meant to simply prop up China's exports.

The G20 agreed in Brisbane, Australia, last year to launch measures to raise their collective gross domestic product growth and create millions of new jobs over the next five years.

The pledge, called the Brisbane Action Plan, entailed hundreds of commitments. Turkey has said their implementation is critical to the credibility of the G20.

But the global growth outlook has been downgraded since the adoption of the Brisbane plan, making the goals harder to reach.

"The global economy is slower than many had hoped and thought it would have been half a year ago," said John Kirton, a political science professor at the University of Toronto, who specialises in global governance issues including the G20.

"And we may have a mini financial crisis or a mini shock out of China, which is having a negative effect in many of the G20 members."

There has been some speculation the finance ministers and central bankers will aim to hash out a new series of measures to boost growth - but that those won't be announced until the heads of government summit in November.

"Why don't they announce a whole set of remedial measures right here, right now?" Kirton said.

Finance chiefs at the summit are also unlikely to be able to avoid discussing the growing migrant crisis across Europe, although they are not expected to take much concrete action.

The issue has a particular resonance in Turkey after a photograph of a three-year-old Syrian boy whose body washed up on a Turkish beach swept social media on Wednesday, spawning outrage at the perceived inaction of developed nations in helping refugees.

Turkey has taken in around 2 million Syrian migrants over the last four years at a cost of more than $6.5 billion.

"We assume it a duty in our G20 presidency in 2015 to call on the international community and the nations to act for human dignity," Labour Minister Ahmet Erdem said on Thursday. (Additional reporting by Orhan Coskun and Nick Tattersall in Ankara and Akin Aytekin in Istanbul; Editing by Nick Tattersall/Jeremy Gaunt)