* Higher equities hurt low-yielding yen
* Commodity currencies fall as oil prices slip on Iran deal
* U.S. pending home sales hit 10-month low last month
* Euro falls vs dollar; room to cut rates more-ECB official
By Julie Haviv
NEW YORK, Nov 25 (Reuters) - The yen tumbled to a six-month low against the dollar and a four-year trough versus the euro on Monday as a deal on Iran's nuclear program eased political anxieties and boosted optimism about economic growth, sending global stocks higher.
The Japanese currency typically falls when share prices rise, with some investors selling the low-yielding yen in search of greater returns with riskier assets such as equities.
The breakthrough accord reached over the weekend in Geneva - between Iran, the United States, China, Russia, France, Britain and Germany - halts Iran's most sensitive nuclear activities and gives it some relief from crippling sanctions, but does not allow the OPEC member to boost oil sales for six months.
Global equity markets, as measured by MSCI's all-country world index of 45 countries and the pan-European FTSEurofirst 300 rose.
In Japan, a major oil importer, shares got an extra boost from a weaker yen to surge 1.5 percent. The Nikkei average has gained almost 11 percent in just over two weeks.
"The market perceives the (inverse) correlation between the yen and the Japanese Nikkei as strong ... it's very much embedded in the market's psyche," said Jane Foley, senior currency strategist at Rabobank.
U.S. stock indices rose, suggesting major averages would extend a rally that has taken them to all-time highs.
In late morning New York trade, the dollar was up 0.4 percent at 101.78 yen, having earlier hit 101.91 yen, its strongest since late May.
Positioning data last week showed speculators increased net short positions in the Japanese currency to their highest in six years.
Traders said some investors were reluctant to be short of dollars before Thursday's U.S. Thanksgiving holiday.
"The yen is being sold off as the funding currency of choice," said Jeremy Stretch, head of currency strategy at CIBC, adding the dollar could be heading towards 102.50 yen, a level last hit at the end of May.
The euro rose as far as 137.98 yen, its highest since October 2009. It last traded flat at 137.24 yen.
The dollar briefly pared gains after data showed contracts to buy previously owned U.S. homes fell for a fifth straight month in October, hitting a 10-month low and adding to signs of cooling in the housing market.
The euro fell against the dollar, however, after European Central Bank Governing Council member Ardo Hansson said he saw more room for the central bank to cut interest rates.
The euro fell 0.5 percent to $1.3498, with analysts and traders also saying lower oil prices may exacerbate concern about disinflationary pressures in the euro zone.
Last week the euro fell as low as $1.3398 after a media report suggested the ECB could opt for negative deposit rates.
ECB Executive board member Benoit Coeure said in Tokyo that slowing price growth, or disinflation, would continue for now, but would not progress to deflation.
Falling oil prices weighed on commodity-linked currencies, with the Canadian dollar last trading up 0.4 percent at C$1.0554.
The Australian dollar was down 0.1 percent at $0.9154, having earlier hit a 2-1/2 month low of $0.9117 due to the threat of intervention by the Reserve Bank of Australia to stem the currency's recent gains.
CitiFX, a division of Citigroup, said that while the Iran deal over the weekend has weighed on oil prices, the maintaining of the oil embargo with Europe meant the shift in supply could be less pronounced in the near term.
Brent oil, however, among the lightest and sweetest blends, could suffer from reduced geopolitical tensions and the prospect of eventual addition of Iranian supply, the firm said.
"While not always a significant driver of Norwegian krona, lower Brent prices could provide a marginal headwind for the Crown," CitiFX said.
"The Canadian dollar as the archetypal oil currency could suffer further headwinds to the extent that further risk premium is removed more broadly," the bank said.