Greece's stock market watchdog on Wednesday said it was maintaining a short-selling ban on the shares of top banks ahead of an imminent recapitalisation process.
"The measure shall be in force (from) October 1 (to) November 9," the capital market commission said in a statement.
"Any additional pressure on the listed stocks of credit institutions could have consequences," it said.
The ban applies to shares of Alpha Bank, Attica Bank, Eurobank, National Bank and Piraeus Bank.
Short-selling occurs when investors sell shares they do not own in anticipation of a fall in their price, fuelling market volatility.
The short-selling ban was imposed in June alongside capital controls when fears of Greece being ejected from the eurozone caused a run on bank deposits.
Since then, Greece has agreed a new, 86-billion-euro ($96-billion) bailout with international creditors and in early September the short-selling ban was lifted for equity derivatives.
In its statement, the commission said "recent political developments" did not justify the continuation of the general ban on short-selling, and that it had "decided to prohibit only the short-selling of shares of the credit institutions".
Greek banks are to be recapitalised by December, before new EU-wide bank rescue regulations that could affect depositors come into play in 2016.
Close to 25 billion euros has been set aside under the latest aid plan to recapitalise Greece's ailing banks, although this amount could change depending on the outcome of stress tests being carried out by the European Central Bank.