REFILE-Russia not expected to stand up for tanking rouble amid sanctions
(Corrects paragraph 5 to show Zurich instead of London, corrects penultimate paragraph to remove extraneous word "when")
* Rouble hits 67.67 vs dlr, its weakest since June 2016
* Analysts expect no real action from c.bank over rouble
By Andrey Ostroukh
MOSCOW, Aug 10 (Reuters) - A threat of more U.S. sanctions has sent the rouble tumbling to its weakest since mid-2016 but authorities are not expected to leap the currency's defence after weathering a similar storm in April, analysts said.
The lack of action by authorities back then is convincing market players now that they will not intervene this time either.
"When we think about what has happened in April, when sanctions were introduced and we saw a similar reaction in the rouble ... this is not a move in the rouble that would make policy makers extremely worried," said Tilmann Kolb, an emerging market analyst at UBS Global Wealth Management in Zurich.
Liza Ermolenko, an economist at Barclays in London, said that given the central bank refrained from intervening in the market in April, it is clear that a more sudden and deeper drop in the rouble would be required to make it step in now.
The authorities have made few public comments on the latest falls, which started on Wednesday, when the U.S. State Department announced a new round of sanctions that pushed the rouble to two-year lows and sparked a wider sell-off over fears Russia was locked in a spiral of never-ending sanctions.
On Friday the central bank said it had tools to prevent risks to financial stability, without specifying what they were.
As in April, the central bank has reduced its daily buying of foreign currency for state reserves this week to lift extra pressure from the rouble, which has fallen by around 15 percent versus the dollar so far this year.
Analysts say the other possible option to support the rouble would be a hike to the key interest rate, now at 7.25 percent, but this also seems to be off the table for now.
"At this stage we don't expect policymakers to resort to rate hikes," Ermolenko from Barclays said.
Kolb from UBS said he would "expect a bigger reaction if we got perhaps towards 70 (roubles per dollar) but this also depends on how we get there, if at all".