UBS has today posted a $862m fourth-quarter pre-tax profit, hit by a slowdown in its flagship wealth management business and weaker earnings in its investment bank. 

On an adjusted basis, fourth-quarter pre-tax profit fell to $860m, under conditions which chief executive Sergio Ermotti described as "historically tough". 

The Swiss bank manages more than $2 trillion of the world's wealth.

It said it saw $7.9 billion in wealth management net new money outflows - a closely watched metric of future earnings - over the last three months of 2018. 

As clients removed risk from their portfolios, traded less and stocked up on cash amid geopolitical tensions, adjusted pre-tax earnings in its flagship wealth management business fell 22%. 

The bank in December had flagged further deleveraging and a trading slowdown amongst wealthy Asian customers worried about ongoing trade wars.

It said today a tepid investor mood would continue dampening first-quarter results.

"Lack of progress in resolving geopolitical tensions, rising protectionism and trade disputes along with increased volatility, which affected investor sentiment and confidence in the second half of the year and particularly in the fourth quarter of 2018, would affect client activity in the first quarter of 2019," it said.

The Swiss bank said its full-year net profit rose to $4.897 billion from $969 million in 2017, when a one-off 2.9 billion franc hit from U.S. tax reforms dampened results. 

Five analysts polled by Reuters on average had forecast a net profit of $4.906 billion for 2018. 

The bank proposed a dividend of 0.70 Swiss francs ($0.7017) for 2018, up from 0.65 Swiss francs the previous year, and said it aimed to buy back up to $1 billion in shares in 2019.