ZURICH (Reuters) -Capital requirements set for UBS under new banking regulations should be "proportionate", as Switzerland attempts to strike a balance between financial sector competitiveness and protecting taxpayers, Finance Minister Karin Keller-Sutter said.

Swiss authorities are weighing up how to overhaul banking rules in a bid to prevent a repeat of the 2023 collapse of Credit Suisse, which led to its takeover by its old rival UBS.

In an interview broadcast on Sunday, Keller-Sutter said UBS was now a very large bank in relation to the size of the Swiss economy, creating a "special situation".

"And so the appropriate protective and preventative measures must be taken; that means liquidity, that means equity capital," she told national broadcaster SRF.

She acknowledged UBS already faced certain stricter capital requirements, including under Basel III rules effective from January that not all countries are implementing identically.

In April, Keller-Sutter said estimates that UBS would have to hold another $15 billion to $25 billion in capital under her government's proposals were "plausible".

Asked in the interview whether the $25 billion figure was still valid, Keller-Sutter said she could not say. In the end, what counted was the whole package of measures, she noted.

"This must be looked at in a proportionate, targeted way," she said, arguing Switzerland must find a compromise between having a competitive financial sector and protecting taxpayers.

Addressing an upcoming parliamentary report into how authorities handled the Credit Suisse crisis, Keller-Sutter stressed that the main blame lay with the bank's management.

Asked about the risk of incoming U.S. President Donald Trump imposing hefty trade tariffs on other countries, Keller-Sutter said it was too early to speculate.

"But of course if such tariffs did come about, it would be poison for world trade," she said.