Some of provider Scottish Widows pension customers have been affected after a technical glitch hit its investment rebalancing system.
The problem has impacted Widows' bespoke lifestyling option, which is available to group personal pension (GPP) investors via advisers or employers.
The option allows customers, through their adviser or employer, to select their own investment mix. The pension fund is then automatically adjusted every quarter to match the preferred mix.
However, a technical glitch has meant investors' adjustments have not been made. It is not known how long the error has been present.
The provider would not confirm how many customers might be affected and said it is in the early stages of investigation.
The provider said it is working to fix the problem "as a matter of urgency". It also asserted customers will receive "appropriate remediation" for problems with their investments.
"Customers affected will not suffer any loss as a result of this error," a spokesperson said.
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