The dollar gained more ground against the other major currencies Thursday on optimism about the economy after a surprise narrowing in the U.S. trade deficit. Analysts predicted that if April U.S. retail sales data, set for release later Thursday, was strong, it could result in more buying of dollars by overseas investors. On Wednesday, the trade deficit fell sharply to its lowest level in six months, coming in well below analysts' forecasts. Concern over the wide U.S. trade and budget deficits has fueled the dollar's weakness over the past year, and the dollar had slipped on analyst expectations that the deficit would hit a new monthly record in March. Instead, the gap between what the United States imports and what it sells to foreign countries narrowed by 9.2 percent to $54.99 billion, from the record monthly deficit of $60.57 billion set in February. That means fewer dollars in the hands of companies that export goods to the United States, increasing demand for dollars. "The data helped dispel much of the pessimism that the U.S. economy's soft patch is set to continue," said Kenji Kobayashi, senior manager of foreign exchange at Bank of Tokyo-Mitsubishi.