HSBC Holdings PLC said it plans to switch outside auditors to PricewaterhouseCoopers's U.K. affiliate, dismissing KPMG LLP's U.K. arm, the auditor it has used for more than 20 years.

The U.K. bank's move on Friday marks the first major auditor change by a U.K. company since the country's antitrust regulators said last month that large companies should periodically consider changing auditors.

HSBC...