By Joshua Franklin and Brenna Hughes Neghaiwi
ZURICH (Reuters) - Switzerland's central bank is set to leave its benchmark interest rate unchanged in negative territory at least until the second half of 2017, according to a Reuters poll of economists.
All 37 economists polled in the past few days predicted the Swiss National Bank (SNB) would keep its target range for three-month Swiss Libor
The median forecast was for the SNB to leave rates unchanged through the second quarter of next year, the end of the forecast horizon. The SNB is also expected to leave interest rates on sight deposits unchanged at -0.75 percent until then.
A rate cut further into negative territory would draw more criticism from banks, insurers and pension funds which have had to adapt to paying a deposit charge on portions of their cash holdings.
The SNB is using negative interest rates, coupled with an unspecified amount of foreign currency purchases, to weaken the Swiss franc and protect exports to the euro zone, Switzerland's biggest trading partner.
A muted market response for the franc to the European Central Bank's decision to cut rates and expand asset purchases last week has lessened the need for the SNB to act on rates, economists said.
"As the latest ECB policy move has actually resulted in a somewhat stronger euro, including against the Swiss franc, the SNB will see no need to reduce either its policy rate or deposit rates more deeply into negative territory," said IHS Global Insight economist Timo Klein.
Maintaining a spread between SNB and ECB interest rates is an important tool for weakening the franc, the SNB has argued.
The ECB last week cut its deposit rate to -0.4 percent from -0.3 percent and dropped its main refinancing rate to zero from 0.05 percent but ECB President Mario Draghi also suggested the central bank had hit its floor for interest rates.
"Pressure on the SNB to cut rates has eased since the ECB said that it did not expect to cut rates further," Capital Economic economist Jennifer McKeown said.
Switzerland's export-reliant economy has labored under a surge in the franc's value after the SNB scrapped its cap of 1.20 francs per euro on Jan. 15, 2015.
It said the policy, in place since September 2011, had become too expensive to maintain.
The SNB has stated repeatedly it expects negative interest rates, coupled with its willingness to intervene in the currency market, eventually to weaken a "significantly overvalued" franc.
The franc has stabilized at around 1.09 francs per euro (EURCHF=), a tolerable level for Swiss exporters and slightly weaker than ahead of the SNB's last policy meeting in December when it also left rates unchanged.
The poll's median forecast was for the euro/franc exchange rate to be at 1.10 francs by the end of 2016.
(Polling by Sarmista Sen and Deepti Govind Editing by Jeremy Gaunt)