* Dollar struggles vs high-yielders as Fed meeting nears
* SNB intervenes in Swiss franc forward market
* Merkel repeats opposition to euro zone bond idea (Recasts top, adds comment, detail, updates prices, changes byline, dateline, previous LONDON)
By Steven C. Johnson
NEW YORK, Aug 22 (Reuters) - The dollar slipped against commodity-linked currencies on Monday as some investors speculated the Federal Reserve would take new measures to boost the ailing U.S. economy, while Swiss authorities moved to drive down the franc.
The Fed will host its annual retreat in Wyoming this week, and recent market turmoil and signs of weaker U.S. growth have fed expectations that Fed Chairman Ben Bernanke may hint at more emergency stimulus for the economy.
At last year's meeting Bernanke hinted at what eventually became a $600 billion 'quantitative easing' bond-buying program, known as QE2.
"The Fed is definitely on people's minds, and you could argue that some of the bounce seen in high-yield commodity currencies is at least in part related to hopes for more policy measures," said Wells Fargo strategist Vassili Serebriakov in New York.
Others anticipate Bernanke will highlight the need to continue supporting the economy, but may stop short of announcing more asset buying. For more see [ID:nN1E77I0NF].
Bernanke could be the "game changer" for the market this week, said Ulrich Leuchtmann, strategist at Commerzbank.
Fed easing increases the amount of dollars in the system, pushing down the currency's value and U.S. interest rates. That encourages investors to seek higher returns in stocks or currencies that carry higher interest rates.
Among the best performers Monday were the Australian dollar
The euro
The latest positioning data shows speculators increased their bets against the dollar last week. [IMM/FX]
"QE3 would probably lead to further dismay among foreign investors and selling of dollars," Citigroup strategists said in a note to clients.
SNB INVOLVED, YEN EYED
The euro and dollar also rose against the Swiss franc
The euro
The franc has soared to record highs against both currencies as fear about Europe's debt crisis and the U.S. economy pushed investors toward the traditional safe haven.
To slow franc appreciation, the SNB has mentioned the possibility of pegging it to the euro. Investors remain on edge that the central bank could sell francs on the spot market, though attempts to weaken the franc this way in 2010 failed.
Traders also speculated that Japan could intervene to weaken the yen. Though up slightly from Friday, the dollar was not far from its all-time low, trading at 76.75 yen
But Credit Suisse currency strategists said that while "the risk of intervention seems to be rising, we think the main impact would be to slow rather than stop yen appreciation."
The euro's gains were limited though by continued worries about the euro zone debt crisis and the perception that officials were moving too slowly to address problems.
German Chancellor Angela Merkel on Sunday rebuffed calls for joint euro-denominated bonds as a way for fiscally weak euro zone countries to borrow. [ID:nL5E7JJ3MN]
"If things start to take a turn for the worse in the euro zone, it's hard to see what they can come up with to help," said Richard Falkenhall, currency strategist at SEB in Stockholm. (Additional reporting by Naomi Tajitsu in London; Editing by James Dalgleish)