UBS said on Monday it was launching a share-for-share exchange to set up a new holding company, UBS Group AG, part of a restructuring drive to ensure it can be broken up more easily in a crisis.

Switzerland's largest lender said back in May it planned to break with its existing structure in which a parent company holds a host of interconnected branches, in order to satisfy regulators' demands for separate legal entities in different regions.

The Swiss bank said in a prospectus it expected to propose a supplementary capital return of at least 0.25 francs a share once it had completed the transaction. The payout will likely be in 2015, based on the current timetable.

"As announced previously, the establishment of a holding company is a significant step in a series of envisaged changes to UBS's legal structure that are intended to substantially improve its resolvability in response to evolving industry-wide 'too-big-to-fail' requirements," the bank said.

The changes to UBS's legal structure will not affect its strategy, the bank said.

The bank released some updated figures as of Aug 31 with the prospectus, which showed retained earnings edged up to 27.1 billion Swiss francs ($28.44 billion) from 26.3 billion francs in the second quarter. Equity attributable to shareholders also rose to 50.8 billion francs from 49.5 billion francs.

UBS reaffirmed that it expected the new structure will allow it to qualify for a capital rebate under Switzerland's too-big-to-fail requirements, resulting in lower overall capital requirements for the bank.

In May, Swiss financial regulator FINMA published provisional rules that would require UBS to hold total capital worth 19.2 percent of its risk-weighted assets by 2019.

In addition to setting up the new holding company, UBS Group AG, the bank also plans on establishing a Swiss subsidiary in mid-2015 and a holding company for its U.S. operations by mid-2016.

The change in structure means UBS's businesses can be separated more easily if one ran into trouble without jeopardizing the others, preventing a repeat of 2008 when Swiss taxpayers had to save the bank from huge losses in the United States.

The previous model of interconnected branches meant the entire business had to be rescued by Swiss taxpayers when it ran up more than $50 billion in U.S. mortgage losses.