British consumers spent slightly more this Black Friday, according to the boss of HSBC Holdings Plc’s UK arm, despite technical problems last week that meant many customers struggled to access the bank’s digital services.

“It was marginally up year-on-year,” HSBC UK Chief Executive Officer Ian Stuart said in an interview with Bloomberg Television on Monday.

Stuart apologized to customers for last Friday’s difficulties, saying the bank had fully restored online services by Saturday evening after issues with a third-party supplier. “It was a technical glitch; it was not a cyber attack,” he said.

He was speaking from the UK’s Global Investment Summit at Hampton Court Palace in London, where Blackstone’s Stephen Schwarzman and JPMorgan Chase & Co. Chief Executive Officer Jamie Dimon are among those attending. The event started with a breakfast hosted by Chancellor Jeremy Hunt with CEOs including UBS Group AG’s Sergio Ermotti and HSBC’s Noel Quinn in attendance.

HSBC is one of sponsors of the event. Stuart said he was positive about the British economy after last week’s Autumn Statement, saying moves to lower the tax burden on business were a “big boost.”

“We are optimistic because the UK economy is proving to be very resilient,” he said. “The capital allowances alone are really good for businesses who are investing. The key is, will the businesses invest to take advantage of those allowances.”

In March, HSBC took over the UK arm of failed US lender Silicon Valley Bank. Stuart said the company had been on a “very steep learning curve” since the deal expanded HSBC’s technology banking capability.

Stuart expects further consolidation among British banks in the coming years, adding there remained “a lot of operators” in the UK.

--With assistance from Katherine Griffiths and Francine Lacqua.