Japanese exporters' selling

Although the U.S. currency maintained its firm tone, its upside against the yen was capped by Japanese exporters' selling, traders said.
The dollar index, a gauge of the greenback's performance against six other major currencies, inched up 0.3 percent to 78.060.
The euro was trading around $1.4285 EUR=, down 0.3 percent from U.S. trading on Dec. 31.

Higher longer-dated U.S. Treasury yields underpinned the dollar's recent gains against the yen, traders said, with benchmark Treasury yields rising above 3.9 percent on Thursday, in sight of last year's high around 4 percent. [US/] US10YT=RR
The dollar was trading around 92.90 yen JPY=, having risen as high as 93.15 yen on trading platform EBS last Thursday, its highest since early September 2009.