ZURICH, June 1 (Reuters) - Major Credit Suisseinvestor Qatar Investment Authority (QIA) has increased its stake in the Swiss bank to 5.01 percent of shares, Credit Suisse said on Thursday.

"In a disclosure report dated May 30, 2017, Credit Suisse Group AG was notified that as of May 24, 2017 the Qatar Holding LLC which is controlled by the State of Qatar held 17.98 percent of the voting rights entered in the Commercial Register (5.01 percent shares; 12.96 percent purchase rights)," Zurich-based Credit Suisse said in a statement.

Qatar Holding is controlled by Qatar Investment Authority, the Gulf Arab state's acquisitive sovereign wealth fund. In a November 2016 disclosure on the Swiss stock exchange, Qatar Holding's share stake was given at 4.93 percent.

QIA is the fourth-largest holder of Credit Suisse shares, according to disclosures by the bank.

The increased stake size follows a roughly 4 billion Swiss franc ($4.1 billion) rights issue by Credit Suisse last month.

In a notice on the Swiss stock exchange announcing the stake increase, "acquisition" is given as the facts and circumstances triggering the obligation to notify.

The bulk of QIA's overall 17.98 percent Credit Suisse holdings is made up by contingent convertible bonds - often referred to as CoCos - which convert into equity if the bank's core capital ratio dips below a certain level.

($1 = 0.9695 Swiss francs)

(Reporting by Joshua Franklin and Ruppert Pretterklieber; Editing by Michael Shields) ((joshua.franklin@thomsonreuters.com; +41583067007; Reuters Messaging: joshua.franklin.thomsonreuters.com@reuters.net))