* Dollar slightly firmer against euro, yen
* ECB willing and able to act if needed at December review
* Aussie outperforms, double whammy hits kiwi hard
By Ian Chua
SYDNEY, Nov 4 (Reuters) - The dollar held on to modest gains on Wednesday having firmed against the euro and yen as on rising Treasury yields, but it was the contrasting fortunes of the Antipodean currencies that stole the show.
A further decline in dairy prices and soft jobs data all but sealed the kiwi's fate as the worst major performer, while a slightly more upbeat outlook on the economy by Australia's central bank put a spring in the Aussie's step.
The dollar index last stood at 97.190, having drifted up 0.3 percent on Tuesday. The euro dipped to $1.0965 after European Central Bank President Mario Draghi reiterated that further easing was on the table for December.
Against the yen, the greenback popped above 121.00, pulling away from a low of 120.60.
"The U.S. dollar and U.S. interest rates rose without any apparent news catalysts. U.S. 10 year treasury yields rose from 2.16 percent to 2.22 percent, a six week high, though market pricing for a Fed hike in December remained at 50 percent," Sean Callow, senior strategist at Westpac wrote in a note to clients.
The Aussie, though, climbed to its highest in a week above 72 U.S. cents and was last at $0.7184. It was well off a recent low of $0.7067.
Aussie bulls took heart after the RBA chose to hold interest rates steady, rather than cut on Tuesday and surprised some by noting that "prospects for an improvement in economic conditions had firmed a little over recent months".
The market shrugged off the central bank's explicit easing bias.
In contrast, the kiwi's underperformance was clear when compared with its Aussie peer, which jumped nearly two full NZ cents towards NZ$1.0800 - its biggest one-day rally in nearly two months.
"Given it moved so swiftly, it hints that the market missed this rally. However, it is not too late as we target 1.09 by year end," said Annette Beacher, chief Asia-Pacific macro strategist at TDSecurities.
Versus the greenback, the kiwi slid to $0.6656, peeling back from highs near 68 U.S. cents set in the past three sessions.
Official data early on Wednesday showed New Zealand posted its first quarterly fall in employment in three years. The data came hours after global dairy prices fell at a second consecutive auction.
Eyes are now on Australia's retail sales and trade data due at 0030 GMT, followed by China's services PMI at 0145 GMT. The week's key event, though, is the U.S. payrolls report on Friday. (Reporting by Ian Chua; Editing by Eric Meijer)