Switzerland's parliament has formally agreed to establish a parliamentary commission (PUK) to look into Credit Suisse's collapse and rescue in a deal engineered by Swiss authorities, the legislative body said on Thursday.

The investigation is only the fifth time such a commission has been established in Switzerland's modern history.

It comes after two sub-committees supported a deeper investigation into how the government, Swiss central bank and financial market regulator acted in the run up to the emergency rescue of Credit Suisse.

Under the rescue deal, UBS agreed to buy Credit Suisse, marking the first rescue of a global bank since the 2008 financial crisis.

The government has provided the banks with 109 billion Swiss francs ($120.32 billion) in financial guarantees to ease the deal, causing widespread uproar in Switzerland.

Next Wednesday the political parties are expected to decide which parliamentarians will make up the 14 seat commission. The investigation's exact mandate has not yet been determined.