(Corrects "fell" to "rose" in describing JPX-Nikkei index movement)
By Joshua Hunt
TOKYO, May 18 (Reuters) - Japanese stocks ended the day flat on Wednesday after the yen see-sawed against the U.S. dollar, rising and falling in strength as investors digested Japan's stronger-than-expected GDP data and U.S. inflation.
The Nikkei share average edged down 0.05 percent to 16,644.69.
The yen gained on the dollar early in the morning session after expectations for further stimulus were hit by data showing Japan's economy expanded at the fastest pace in a year in the first quarter, rebounding from the previous quarter's contraction and beating median market forecasts.
A stronger yen hurt the profit outlook for exporters' shares. The currency spent much of late morning and afternoon vacillating between strength and weakness as the market attempted to digest GDP data that favoured yen strength and stronger expectations of further Fed easing that would favour yen weakness.
The broader Topix edged up 0.2 percent to 1,338.38 and the JPX-Nikkei Index 400 rose 0.2 percent to 12,104.18.
The U.S. Labor Department said its consumer price index increased 0.4 percent last month, the largest gain since February 2013, after rising 0.1 percent in March. That took the year-on-year increase in the CPI to 1.1 percent from 0.9 percent in March. (Reporting by Joshua Hunt; Editing by Eric Meijer)