North American gold-backed exchange-traded funds added more tonnes than those of Asia and Europe combined during January, accounting for more than half of global net inflows, the World Gold Council said on Thursday.

North American inflows added 21.5 tonnes valued at $941 million. That was a 1.8 percent increase in assets under management over December 2017, the council said. Total assets under management in North America were at 52.6 billion in January.

The spike in North American gold-backed fund investment was a function of gold prices extending their late-2017 rally into January on the back of a weak greenback, the WGC said. Gold prices increased close to four percent in January.

“Gold demand through gold-backed ETFs continues to grow. Gold’s price momentum combined with a weakening U.S. dollar helped...Increased activity in the options market also supported this trend,” said Juan Carlos Artigas, the council's director of investment research.

United States-listed ETFs alone accounted for 73 percent of global net inflows in January, the WGC said. This effectively reversed the 2017 theme of European funds dominating net inflows.

European funds added 7.6 tonnes of gold in January, valued at $35.3 million. This was a 0.08 percent increase in assets under management over December, 2017. By the end of last month, there were 41.8 billion total gold-backed assets under management in Europe.

Asian funds had net outflows of 1.4 tonnes for January. Those assets under management totaled 33.2 million and were down one percent from the month before. Asia's total gold assets under management was at 3.3 billion in January.

For January, global gold-backed ETFs collectively totaled 2,396 tonnes valued at $103.6 billion. Funds added 27.6 tonnes of gold during the first month of the year, increasing global assets under management by five percent from December 2017, according to the data.

This article was provided by Reuters.