* Yen falls after PM resigns, euro steady
* World stocks ease, extending May's nearly 10 pct drops
By Dominic Lau
LONDON, June 2 (Reuters) - The yen fell on Wednesday, unsettled by the Japanese prime minister's resignation, while world equities and commodity prices slipped on concerns about the impact of the euro zone debt crisis on global growth.
The euro steadied, helped by comments from some of the world's biggest central banks that they would not stop investing in the single currency. It was little affected by a report on state-owned Iranian TV that Iran would sell 45 billion euros of reserves to buy dollars and gold. [
]But there were still signs of tension in euro zone assets. The premium investors demand to buy peripheral government bonds rather than euro zone benchmark Bunds rose.
The U.S. currency rose to a two-week high of 91.97 yen <JPY=>, according to Reuters data, as investors sold due to fears over political instability and the fact that Yukio Hatoyama's expected replacement, Finance Minister Naoto Kan, has previously advocated a weak yen.
Kan surprised markets earlier this year by saying he wanted the yen to weaken more and that most businesses were in favour of a dollar/yen rate around 95 yen. Since then he has mostly toed the ministry line that stable currencies are desirable and markets should set foreign exchange levels.
"If the position does fall to Kan, then the bias will be towards a slightly weaker yen," said Gavin Friend, currency strategist at nabCapital.
The resignation news had also weighed on Tokyo's shares, with the Nikkei average <
> down 1.1 percent.World stocks measured by the MSCI All-Country World Index <.MIWD00000PUS> slipped 0.6 percent, on the back of weaker markets in Asia and Europe. The index fell nearly 10 percent last month, its worst monthly loss since February 2009. In Europe, the FTSEurofirst 300 <
> index lost 0.6 percent, with oil major BP <BP.L> falling 1.9 percent to extend the previous session's 13 percent slump.The U.S. government has launched a widely expected criminal and civil investigation into BP's massive oil spill, ratcheting up pressure on the beleaguered British oil company.
EURO STEADY
The euro <EUR=> steadied at $1.2226 after rising to around $1.2249 after official sources in Brazil, India, Japan, Russia and South Korea said that there were no alternatives to the dollar and the euro as reserve currencies in the near term. [
]The euro is down more than 14 percent against the dollar this year on fears stemming from Greece's sovereign debt problem and possible contagion risks which sparked a sell-off in financial markets around the world.
The weakness in the single currency has raised concerns whether central banks around the world, especially those surplus rich countries, will trim their holdings of the euro.
However, the Italian/German 10-year bond yield spread widened to 158 basis points (bps) versus 151 bps at Tuesday's settlement close. The equivalent Spanish spread was around 6 bps wider on the day at 175 bps.
"There's still lingering concerns about the fiscal positions of some countries given the Spanish downgrade on Friday," said Nick Stamenkovic, strategist at RIA capital markets.
Yields on benchmark 10-year Bunds <EU10YT=RR> fell 3 bps to 2.653 percent, while those on 10-year Treasuries <US10YT=RR> rose 2 bps to 3.2848 percent.
In the commodity market, crude prices <CLc1> dipped 0.5 percent to trade above $72 a barrel, and copper prices <MCU3> eased 1.7 percent. (Additional reporting by Jessica Mortimer, Naomi Tajitsu and William James)
(Editing by Jason Webb)