A weaker dollar makes gold cheaper for holders of other currencies, while also increasing the metal's appeal as a hedge.
The dollar nursed modest losses against the yen and euro early, and suffered bigger falls versus commodity currencies led by the Canadian dollar.
Weakness in the greenback was also prompted by sluggish U.S. economic data released on Wednesday.
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U.S. industrial output posted its biggest drop in more than 2-1/2 years in March in part as oil and gas well drilling plummeted, highlighting the negative impact of lower crude prices and a strong dollar on the economy.
The dour report was the latest sign that growth slowed sharply in the first quarter and suggested the U.S. central bank could delay raising interest rates until later this year.
Investors believe a hike in U.S. rates could dent demand for bullion, a non-interest-paying asset.
Analysts have made big cuts to expectations for gold and silver prices this year and next after the metals, weighed down by the prospect of higher U.S. interest rates, failed to recover last year's losses in early 2015.
A poll of 38 analysts and traders conducted by Reuters over the last month returned a median forecast of $1,209 an ounce for gold this year, down from $1,234 an ounce in a similar poll conducted in January.