FOREX-Dollar climbs to 3-month peak vs yen, but down vs euro

* Dollar recovers vs yen, ADP data a concern

* Japanese selling drives yen to 3-month low vs dollar

* Euro supported by month-end demand, fiscal woes linger

* Dollar on track for best quarter in a year

* Euro falls to record low vs Swiss franc (Recasts, updates prices, adds detail, adds quote)

NEW YORK, March 31 (Reuters) - The dollar touched a three-month high against the yen on Wednesday and although it slipped against the euro, the greenback scored its best quarterly performance in 12 months on bets the U.S. economy will continue to improve.

With the U.S. economy being compared favorably with problems in the peripheral euro-zone nations and Japan not expected to exhibit dramatic growth, the dollar should at least hold its own in the coming months -- if not go higher.

The dollar rose as high as 93.63 yen overnight, its highest level since early January, as investors rang in the start of a new Japanese fiscal year by selling the Japanese currency.

The euro also gained on the yen, rising to 126.55 yen, its highest level since early February.

For the first quarter, an index measuring the dollar against six major currencies rose 4 percent -- its best quarterly performance since the first quarter of 2009. The euro lost 5.6 percent against the dollar this quarter, while sterling fell 6 percent.

Expectations that the Federal Reserve will raise interest rates from record lows before central banks in Japan and Europe tighten monetary policy also boosted the dollar.

Trading, however, was volatile after an ADP report showed a surprising decline in U.S. private-sector jobs in March, sparking concern about the pace of the U.S. economy's recovery.

But after falling briefly below 93 yen, the dollar rebounded, with analysts expecting a government payrolls report on Friday to show the economy added 190,000 jobs in March, albeit aided by temporary government hiring for the 2010 U.S. Census.

Private-sector employers cut 23,000 jobs this month, ADP Employer Services reported. Economists polled by Reuters had expected a gain of 40,000 jobs.

"The negative figure was a bit jarring. People have been focused on private hiring because it should remove the noise of temporary Census-related hiring," said Brian Kim, currency strategist at UBS in Stamford, Connecticut.

YEN FALLS

The dollar was last up 0.7 percent at 93.48 yen, near a session peak, after dipping to 92.76 yen after the ADP report.

Traders said Japanese banks, hedge funds and life insurers remained heavy dollar buyers after the greenback broke above 93 yen. The Japanese currency also hit a five-week low against the pound.

"With the fiscal year-end repatriation completed, the yen has been under pressure and remains so today," said Marc Chandler, global head of FX strategy at Brown Brothers Harriman in New York, in a note to clients.

"Full liquidity will not return to the foreign exchange market until next Tuesday, and this may also encourage some position adjusting."

EURO UP, BUT GREECE A 'WILD CARD'

The euro rose 0.7 percent to $1.3510, boosted partly by quarter-end demand, though traders said further gains were likely to be slight as markets remained worried about a Greek debt crisis.

The spread between Greek and German 10-year benchmark bonds widened on Wednesday, when Moody's Investors Service downgraded five Greek banks.

"Expect range-bound movement until summer with the wild card being Greece," said Joseph Trevisani, chief market analyst at FX Solutions in Saddle River, New Jersey. "The dollar is still the safe-haven currency and the euro will remain weak until the Greek problem is settled or their debt rollover in April and May is completed and accepted by the market. If there is any contagion, the dollar will soar."

Sterling rose 0.8 percent to $1.5192, its fourth day of gains, while the dollar fell 1.4 percent to 1.0511 Swiss francs, coming off the lowest since late January in earlier trading, according to Reuters data.

The euro fell to a fresh record low against the Swiss franc at 1.4210 Swiss francs before coming off the low to trade at 1.4240 francs. (Reporting by Nick Olivari and Steven C Johnson; Editing by Jan Paschal)