By Myra P. Saefong
SAN FRANCISCO (MarketWatch) -- The U.S. dollar index edged higher Tuesday as the euro lost ground against the greenback. Traders digested data showing an unexpected increase in German investor sentiment in April as well as news that an auction of government debt in Spain saw higher borrowing costs though demand was also up. The dollar index DXY +0.02% , which tracks the greenback against a basket of six rivals, was last at 79.601, up from 79.530 late Monday in North American trading. The euro EURUSD -0.2435% bought $1.3108, down from an earlier high of $1.3173 and compared with $1.3141 late Monday.
