Swiss finance minister says unlikely UBS would leave its home base

ZURICH, Sept 26 (Reuters) - Switzerland's finance minister said it was unlikely that UBS would leave its Swiss base after this week's upper house parliamentary vote in favour of tougher capital rules.

Such a move would be more expensive than the new capital rules and legally complicated, Karin Keller-Sutter told CH Media after UBS Chairman Colm Kelleher last week warned that the bank could ​rethink its ⁠Swiss base if capital rules became too harsh.

UBS was dealt a blow on Wednesday when the upper house voted in favour of tougher capital ​rules that the bank estimates could require it to hold about $18 billion in additional capital.

Lawmakers supported a proposal that would ​require UBS to back its foreign units with 90% Common Equity Tier 1 ⁠capital, rejecting a proposal favoured by UBS for 50% CET1 capital and 50% Additional Tier ​1 (AT1) capital, which is cheaper to hold.

Keller-Sutter said UBS "went all out", probably having assumed it would get its way in parliament. She said the Swiss government had already made some compromises with the bank, a notion UBS rejected in comments earlier this week. 

UBS declined further comment on Saturday. 

(Reporting by Marleen Kaesebier in Zurich; Editing by Alexander Smith)