ZURICH, June 30 (Reuters) - The Swiss National Bank sold 32.3 billion Swiss francs ($35.93 billion) worth of foreign currencies during the first quarter of 2023, it said on Friday, as the central bank stepped up its campaign to bolster its safe-haven currency to fight inflation.

It marks the fourth quarter in a row since the SNB switched from buying forex to selling, and represented an increase from the 27.3 billion francs the central bank sold in the last three months of 2022. ($1 = 0.8989 Swiss francs) (Reporting by John Revill Editing by Tomasz Janowski)