* Dollar/yen continues decline; BoJ in focus
* ECB easing expectations, election jitters hurt euro
* Aussie dollar hit by cenbank comments, iron ore slide (Adds quote, updates prices)
NEW YORK, May 20 (Reuters) - The dollar fell against the yen on Tuesday for a fifth straight session, undermined by a persistent drop in U.S. Treasury yields, which analysts say reflects uncertainty about global growth prospects.
The greenback could decline further against the yen if the Bank of Japan does not expand its asset purchase program. On Wednesday, the Japanese central bank is widely expected to keep its policy unchanged at a two-day meeting, but the market will be focused on BoJ Governor Haruhiko Kuroda's news conference.
"Kuroda may continue to highlight an improved outlook for the Japanese economy, and it seems as though the BoJ will carry its current (monetary) policy into the second half of the year," said David Song, current analyst at DailyFX, a unit of FX broker FXCM in New York.
"That said, dollar/yen no longer looks like a one-way trade as the BoJ softens its dovish tone for monetary policy, and a greater deviation in the policy outlook may trigger a further decline in the exchange rate," he said.
The Australian dollar, meanwhile, fell to a two-week low against the greenback, hurt by a slide in prices of iron ore, the country's biggest export earner.
But gains in the U.S. dollar against the Australian currency failed to give the greenback a lift against the yen, which has been on a five-day winning streak as U.S. Treasury yields have softened in four of the last six sessions.
In late trading, the dollar fell 0.2 percent to 101.29 yen . The pair also traded below its 200-day moving average - a key technical gauge - for a second straight day.
"The strong correlation between dollar/yen and Treasury yields continue to be the main driver," said Joe Manimbo, senior market analyst at Western Union Business Solutions in Washington. "Part of that is due to renewed concerns about the health of the global economy."
Investors have voiced concern about the U.S. housing sector, which could dampen growth in the world's largest economy. They are also worried about China's economic outlook, a major driver of the Aussie dollar.
Late on Tuesday, the Australian currency slid 0.8 percent to US$0.9254, after earlier dropping to US$0.9251, its lowest since May 5.
The Aussie has recovered solidly from lows reached in late January, but worries over the pace of growth in China continue to weigh broadly on its outlook and Reserve Bank deputy governor Guy Debelle said potentially slower capital inflows to Australia pointed to more weakness.
The euro, meanwhile, slipped 0.1 percent against the dollar to $1.3698.
The euro zone currency could face more of a headwind ahead of potentially destabilizing European Parliament elections this week, where votes for anti-austerity, euroskeptic parties look set to increase. Expectations of imminent easing from the European Central Bank have also weighed on the euro's outlook. (Editing by G Crosse)