BERN, June 20 (Reuters) - The Swiss National Bank (SNB) has to keep monetary policy loose and remain ready to intervene on currency markets if needed to keep a lid on the the clearly overvalued Swiss franc, Chairman Thomas Jordan told a conference on Tuesday.
The difficult currency situation meant it made no sense to reduce interest rate differentials with other economies at this stage, he said.
"The balance of interests that we always make in this regard speaks very clearly at the moment for continuation of our expansive monetary policy," he said.
The central bank this month kept negative rates on hold at its quarterly policy review. (Reporting by Silke Koltrowitz and Oliver Hirt; Editing by Michael Shields)