MOSCOW, Nov 19 (Reuters) - The Russian rouble gave up early gains on Friday, sliding back past 73 to the dollar, as oil prices swung from positive to negative and geopolitical tensions depressed sentiment. By 1058 GMT, the rouble was 0.6% weaker against the dollar at 73.47 , nearing a low hit on Tuesday. That level was the weakest point since Sept. 21, discounting a seconds-long drop on the Moscow Exchange on Oct. 22 that was probably caused by a trading error. It had lost 0.2% to trade at 83.01 versus the euro .Concerns about a Russian military buildup near Ukraine and a migration crisis in Belarus have stoked volatile trade this week. Although the rouble is set to draw support from record high prices for natural gas in Europe, the strained relations with the West could offset the impact. read more"West-Russia tension continues to simmer, if not fester," BCS Global Markets said in a note. Russia"s Economy Ministry expects the rouble to trade at 71-72 versus the dollar at the start of 2022, the Interfax news agency cited Deputy Economy Minister Polina Kryuchkova as saying. She also said the ministry forecasts fourth-quarter economic growth of around 3% year-on-year. Russia"s economy expanded by 4.3% year-on-year in the third quarter, a slowdown in growth following its strongest leap since 2000 in the previous quarter. Brent crude oil , a global benchmark for Russia"s main export, pared gains to fall 1.8% to $79.77 a barrel following a request from the United States for a coordinated move to cool global energy prices. read more The oil price swing sent Russian stocks to nearly two-month lows. The dollar-denominated RTS index (.IRTS) was down 1.7% to 1,731.6 points, after earlier touching its weakest point since Sept. 22 of 1,728.94 points. The rouble-based MOEX Russian index (.IMOEX) was 1.4% lower at 4,037.5 points, its lowest since late September. Russia"s second-largest bourse, the SPB Exchange, raised around $175 million in an IPO on Thursday, while lender VTB (VTBR.MM) said on Friday it had sold a 17.28% stake in food retailer Magnit. read more For Russian equities guide see For Russian treasury bonds see