By Noele Illien

BERN (Reuters) -Swiss financial regulator FINMA said on Wednesday it plans to carry out 40 reviews of UBS and two stress tests this year on the bank after its 2023 takeover of rival Credit Suisse heightened concerns about "too big to fail" lenders.

FINMA laid out plans for regulating the country's last remaining global systemic bank in its 2023 annual report as the regulator doubled down on its calls for more powers.

"Forty on-site supervisory reviews are planned at UBS in Switzerland and abroad, as well as two in-depth stress tests this year," said Thomas Hirschi, FINMA's head of the banks division.

The majority of the reviews would be carried out in Switzerland, Hirschi said, and a stress test would be done in each half of the year.

Previously, FINMA has not published results of such tests or how many it has done. In other countries, banks are required to carry out the test at least once a year.

FINMA has in the past carried out tests on banks to assess institutions' resilience in extreme economic situations.

These encompassed measures including loss potential analyses, reviews of banks' mortgage lending portfolios as well as their interest rate risks.

The supervisory authority said its activities focus on the risks that come with UBS's integration of its former rival Credit Suisse, including operational stability. FINMA president Marlene Amstad told reporters at a press conference the regulator expected there would be a significant increase in liquidity requirements for UBS, as well as other systemically relevant banks, in the future.

UBS declined to comment.

She said the major outflows Credit Suisse experienced in a short timeframe in October 2022 played a role in these changes, but declined to give any figures.

"This experience has been incorporated into these new requirements, and you can really assume a significant increase in liquidity here and already now," she said.

The regulator said it was also focusing on the combined bank's capital and liquidity planning and said UBS's recovery and emergency planning post-merger will be critically reviewed.

The regulator has come under fire for its supervision of Credit Suisse, and has defended its role in the meltdown which eventually triggered the biggest rescue of a bank since the global financial crisis of 2008-2009.

FINMA said it believed additional tools will enable it to fulfil its supervisory and enforcement job more consistently.

In its appraisal of the sector, FINMA identified a number of serious shortcomings, notably in the areas of money laundering, mortgage lending and cyber risks. It urged the banks concerned to remedy these shortcomings without delay.