UBS Group AG is buying back $7.9 billion of old Credit Suisse bonds, its biggest move yet to shrink the debt load it inherited when taking over its crosstown rival. The Swiss lender's purchase, announced on Friday, is the biggest such buyback so far, based on data compiled by Bloomberg. The legacy debt on UBS books now stands at around $29 billion, down from the equivalent of around $90 billion at the time of the government-brokered takeover in 2023, based on Bloomberg calculations.

The latest tender offer is helping speed up the payback of this debt, which has been falling in size thanks to bonds maturing in recent years. It was done as part of a "proactive management" of UBS' funding and total loss-absorbing capacity, as well as to optimize interest expenses, the bank said when first announcing the offer last week. It ended up boosting the maximum offer amount on a group of these bonds twice, first from $2 billion to $4 billion earlier this week and then to $5.9 billion.

A representative at UBS declined to comment.