Wells Fargo & Co (WFC.N) posted an 18 per cent rise in fourth-quarter profit on Friday, driven by a one-time tax benefit related to President Donald Trump's new tax laws.

Net income applicable to shareholders rose to $5.74 billion, or $1.16 per share on GAAP basis, in the quarter ended Dec. 31, from $4.87 billion or 96 cents per share a year ago.

The quarter included a $3.35 billion one-time boost from writing down its deferred tax liabilities to reflect the new U.S. corporate tax rates. 

Shares of Wells Fargo were down 1 per cent at US$62.32 in premarket trading.

The company, which has been struggling to cut costs in the wake of a sales practices scandal, said it expects full-year 2018 total expenses of US$53.5 billion to US$54.5 billion.

Analysts and investors have kept close tabs on the San Francisco-based lender's expenses, which topped 60 cents per dollar of revenue after the scandal erupted in September, 2016. The bank has struggled to improve that key efficiency metric.

It reported non-interest expenses of $16.80 billion for the fourth quarter, bringing total non-interest expenses for the year to $58.48 billion.

Analysts had estimated on average that non-interest expense would be $54.62 billion for 2017.

Overall revenue rose 2.2 per cent to $22.05 billion, supported by its business lending segment.