ZURICH (Reuters) -UBS could be seen as being too big for Switzerland following its takeover of Credit Suisse, former Swiss Finance Minister Ueli Maurer said on Saturday, with measures needed to reduce the risks of the enlarged bank.

"If you look at the numbers alone and compare UBS with the Swiss economy, it is too big," Maurer told newspaper Tages-Anzeiger. "Therefore, the risk must be reduced."

At around $1.7 trillion, UBS's balance sheet is double the size of annual Swiss economic output, giving the bank exceptional weight for a major economy.

Should the bank fail, there are no local rivals left to absorb it, while the cost of nationalisation could severely damage public finances, experts have warned.

Reducing risks was primarily the responsibility of shareholders via their choice of board members, Maurer said.

"They must take responsibility, not the taxpayers in the end," said Maurer, who left office months before the final collapse of Credit Suisse in March 2023.

"Legislative measures must also be examined," said Maurer, who also defended himself after a recent parliamentary report raised questions about his actions as the Credit Suisse crisis worsened at the end of 2022.

The Swiss government last year laid out plans for tougher capital requirements for UBS and Switzerland's three other big banks in a bid to make the financial sector more robust after Credit Suisse's demise.

Details of the exact capital requirements are yet to emerge, but the possibility that UBS could be made to hold $15 billion to $25 billion in additional capital has met resistance from the bank.

Maurer said if the capital requirements were too high, Swiss banks would no longer be competitive and may look to be based elsewhere.

"For the Swiss economy with its many international multi-nationals, a large bank is a locational advantage," he said. "But risks must be minimized."

UBS declined to comment on the interview. The bank's CEO Sergio Ermotti earlier this month told Migros Magazine that UBS had enough capital to cover potential problems.

The bank supported many of the Swiss government's proposals to improve banking regulation, but they had to be targetted and proportionate, Ermotti told the magazine.