MOSCOW, Nov 22 (Reuters) - The rouble fell to its lowest since mid-2021 on Monday, coming within a whisker of crossing the 75 threshold against the dollar, while stocks plummeted to lows not seen since late August as geopolitical risks caused a sell-off in Russian assets. The rouble has come under selling pressure this month on Western concerns over possible Russian military intervention in Ukraine. But Moscow has dismissed such suggestions as inflammatory and complained about increasing activity in the region by the NATO military alliance. read more With a slide already underway, the rouble fell further after Russia"s SVR Foreign Intelligence Service likened the situation to the lead-up to the war in Georgia in 2008. read more Reports of Russian troops near the Ukrainian border remained "frightening" for foreign investors, said a dealer at a major Russian bank in Moscow. Kremlin spokesperson Dmitry Peskov on Monday reiterated the movement of troops within Russian territory posed no threat to anyone, but said Moscow was alarmed by a U.S.-backed push to supply Ukraine with sophisticated weapons. read more By 1337 GMT, the rouble was 1.6% weaker against the dollar at 74.64 , earlier touching 74.99, its weakest point since July 8. The currency could weaken to the 75-77 range on rising geopolitical tensions in the short-term, said Dmitry Polevoy, head of investment at Locko-Invest. The rouble shed 1.4% to trade at 84.17 versus the euro , a seven-week low. "Russia is likely to remain out of favour as long as the political chest thumping and sabre rattling continues," said BCS Global Markets in a note. Russia"s risk measured by five-year credit default swaps that reflect the cost of insuring exposure to sovereign debt jumped to 105.67 basis points , its highest since April 22. Sales of equities and OFZ treasury bonds, as well as increased FX buying by the finance ministry this month, are also exerting strong pressure on the rouble, said Alor Broker chief analyst Alexei Antonov. The default risk of state technology corporation Rosnano, which on Friday said it had discussed possible restructuring scenarios at a meeting with creditors and major bondholders, could also add to downside pressure on the rouble. Brent crude oil , a global benchmark for Russia"s main export, was down 0.3% at $78.68 a barrel, putting further strain on Russia"s struggling stock indexes. The dollar-denominated RTS index (.IRTS) was down 4.9% to 1,638.7 points, earlier touching its lowest since Aug. 26 at 1,630.03 points. The rouble-based MOEX Russian index (.IMOEX) was 3.3% lower at 3,884.5 points, a level not seen since Aug. 27. Reporting by Alexander Marrow, additional reporting by Andrey Ostroukh and Vladimir Abramov; Editing by Timothy Heritage, Ed Osmond, Kirsten Donovan