Swiss banking giant UBS reported Monday that its profits plummeted 63 percent last year due to US tax reforms that hit fourth-quarter earnings.

It said annual net profit dropped to 1.16 billion Swiss francs (900 million euros, $1.01 billion) for the year.

During the last three months of 2017 the bank suffered a net loss of 2.2 billion Swiss francs as it took a charge of 2.87 billion Swiss francs due to changes in US tax laws.

Without the charge against earnings, the bank said it would have posted a net profit of 641 million Swiss francs for the fourth quarter.

Changes in US tax law have forced banks that operate in the United States to book considerable one-time losses in the final quarter of last year, but are expected to be favourable to them going forward.

"2017 was an excellent year for us. We delivered stronger financial results and met our net cost reduction target," chief executive Sergio Ermotti said in a statement.

"Greater regulatory clarity means we can open a new chapter for UBS, allowing us to sharpen our focus on growth across our businesses, make further investments in technology and deliver attractive returns to shareholders."