ZURICH (Reuters) - The merger of the Swiss units of UBS and Credit Suisse could be completed as early as July 1, a senior executive at UBS was quoted as saying on Tuesday.

UBS, which acquired its former rival Credit Suisse last year after the bank's collapse, had previously indicated the two units would be combined during the third quarter.

Sabine Keller-Busse, president of UBS Switzerland, told the Neue Zuercher Zeitung newspaper in an interview that the plan was progressing "very well".

"The merger could by done by July 1, 2024," she said.

Customers will start transferring to UBS's IT systems in the course of 2025, Keller-Busse said.

The merger of the parent companies of UBS and Credit Suisse concluded at the end of last month.

UBS's absorption of Credit Suisse has left Switzerland with a single global bank, which has a balance sheet around twice the size of the country's annual economic output.

How UBS progresses in the integration of its longtime competitor is a key yardstick of the deal's success.

Keller-Busse, who reiterated that there would be 3,000 layoffs in Switzerland due to the overall merger, was also asked whether she would like to succeed UBS CEO Sergio Ermotti, who is expected to step down during the next three years or so.

She is regarded as one of the potential candidates.

"I have one of the most interesting jobs in the banking industry," she told the paper. "That's what I'm concentrating on, as I always have. All this speculation is irrelevant to me."

(Reporting by Oliver Hirt, Writing by Dave Graham; Editing by Mrigank Dhaniwala)