ZURICH, Aug 23 (Reuters) - The Swiss National Bank will not be able to reduce its huge balance sheet -- built up during its campaign to rein in the strong Swiss franc -- for years, if ever, alternate governing board member Thomas Moser said on Thursday.
The SNB's balance sheet has expanded to more than 120 percent the size of the entire Swiss economy, a higher proportion than other central banks like the European Central Bank and the Bank of Japan.
"The size of the balance sheet is not a goal or objective of the SNB, its expansion is the result of our policy," Moser told an event in Zurich, citing the central bank's goal to check the soaring Swiss franc.
Reducing the size of the balance sheet depends on what happens in the currency markets, "although the suspicion is that it will take a very, very long time," Moser said. "But the size of the balance sheet does not affect our ability to carry out monetary policy," he added. (Reporting by John Revill; Editing by Michael Shields)