* China rejects U.S. yuan criticism ahead of Wen speech
* Trichet says financial system too fragile at present
* Putin to speak after missiles olive branch
* Annual CEO survey shows confidence nosedives to new low
By Mike Dolan and Jason Subler
DAVOS, Switzerland, Jan 28 (Reuters) - Confidence among the world's top bosses meeting in Davos has evaporated and European Central Bank chief Jean-Claude Trichet said on Wednesday a too fragile financial system needed reform.
But a brewing currency row between the United States and China cast doubt on the political will to act in concert. Chinese Premier Wen Jiabao and Russian Prime Minister Vladimir Putin will both address business and political leaders in the Alpine ski resort later on Wednesday, to offer their remedies for the worst economic crisis in 80 years.
Business chiefs and policymakers here for the four-day World Economic Forum said there was no easy solution to the credit crisis that has torpedoed global growth and major government programmes are needed.
Crisis-hit bankers are thin on the ground at the snow-covered mountain town, leaving policymakers to work behind the scenes on ways to fix the financial system, ahead of a summit of the G20 group of big and emerging countries in April and a G8 summit in July.
Trichet told Reuters the G20 was doing "good work" on policies to drag the financial system back into health but that profound reforms were needed.
"Everybody can see the present system is too fragile, and we have to reintroduce an element of resilience ... and we need to do that without any consideration of any kind of vested interest," he said.
Corporate chiefs are still reeling.
"There are no silver bullets. My sense is 18 to 24 months of a very tough economic environment," Maria Ramos, chief executive of Transnet, South Africa's rail and logistics company, told Reuters.
"Forty percent of the world's wealth was destroyed in the last five quarters. It is an almost incomprehensible number," said Stephen Schwarzman, chairman of the leading private equity company Blackstone Group. "Business will be very different."
CURRENCY ROW
Ahead of Wen's speech, a row intensified over Beijing's exchange rate policy after new U.S. Treasury Secretary Timothy Geithner branded China a currency manipulator last week, using a term the previous administration avoided for years.
A Chinese diplomat said on Wednesday Washington had enough evidence to know China does not manipulate its exchange rate.
"I don't think it's fair all of a sudden to change the position of the U.S. government," the diplomat said in London, one of a number of European capitals Wen will visit after Davos.
Putin will meet privately with Wen in Davos to share ideas on how the powers can cooperate on addressing economic problems. No top officials from the new Obama administration are here.
Russia's stance will also be closely scrutinised. Putin's spokesman said he would reach out to investors, who have been shaken by the crisis gripping Russia's economy, but he has previously blamed the United States for "infecting" others.
However, Moscow offered Washington an olive branch on Wednesday, halting a plan to counter a proposed U.S. missile defence shield by stationing its own missiles near Europe's borders, the military was quoted as saying.
DOOM AND GLOOM A PricewaterhouseCoopers poll of more than 1,100 CEOs set a grim backdrop to the annual gathering. Just 21 percent of CEOs said they were very confident of growing revenue in the next 12 months, down from 50 percent a year ago.
Hopes for a short "V"-shaped recession appear to have evaporated with most business leaders expecting no more than a slow and gradual recovery over the next three years.
"The three-year view is a bit better but the bad news is it is not that much better," said Tony Poulter, global head of consulting at PwC.
Delegates in Davos were united in the view that an economic upturn was some way off.
Stephen Roach, Morgan Stanley's Asia chairman, agreed the next three years would be tough.
"The concept of a vigorous 'V'-shaped recovery is for business cycles of the past but not for this post-bubble, post-crisis business cycle. It is going to be a long slog in 2010, in 2011," he told Reuters.
The International Monetary Fund forecast the world economy would slow to a near standstill this year, warning that deflation risks were rising.
That grim scenario has left sovereign fund Dubai International Capital wary of making big long-term investments even though it sees asset prices at reasonable levels.
"We're still very nervous about making some big bets -- we see the financial crisis getting worse. There's not going to be a magic wand solution to the problem," Chief Executive Sameer al-Ansari told Reuters.
For full coverage, blogs and TV from Davos go to www.reuters.com/davos (Reporting by Ben Hirschler; Writing by Mike Peacock; Editing by Richard Hubbard and Erica Billingham)