LONDON, July 17 (Reuters) - Aluminium prices rose further from three-month lows on Tuesday as traders were forced to abandon short positions by the high cost of rolling them forward. Benchmark aluminium on the London Metal Exchange traded up 0.5 percent at $2,065 a tonne in official rings after touching $2,021.50 on Friday, the lowest since April 6. The LME's July monthly contract expires on Wednesday and the cost of rolling a position to August was $53 per contract after surging to $68 on Monday. "There's been an almighty squeeze," said ING analyst Oliver Nugent. Investors who had borrowed aluminium to bet on lower prices were likely to have shied away from the cost of rolling those bets forward and instead bought out their positions, boosting prices, he said. But the gains were likely to be short-lived, he added, with investors unwilling to pile in until it is clear whether the United States will ease sanctions on Russia's Rusal. Rusal is the largest aluminium producer outside China and the sanctions, imposed in April, disrupt its access to global markets. ALUMINIUM SPREADS: Alongside the high cost of the July-August roll, the premium of cash aluminium over the 3-month contract soared this week to $51.50, close to April's 11-year high of $52, before settling back to $42.75. STOCKS: Some investors have delivered metal to settle short positions. On-warrant aluminium stocks in LME-registered warehouses rose by 28,350 tonnes to 1,004,925 tonnes, the first time they have been over the 1 million mark since April and up from around 886,000 tonnes a month ago. MALSTX-TOTAL TECHNICALS: Aluminium faced technical resistance at a downtrend line and Monday's high, both around $2,075, brokers Marex Spectron said. CHINA ECONOMY: China's state planning agency said a 2018 economic growth target of around 6.5 percent could be achieved, a day after data showed slightly slower growth for the second quarter and the weakest expansion in factory activity in two years in June. Weaker growth in China, the largest consumer of metals, would push prices lower. OTHER METALS: LME copper did not trade but was bid down 0.3 percent at $6,175 a tonne, zinc traded 1.9 percent higher at $2,522 a tonne, lead was bid up 0.3 percent at $2,182 a tonne, tin traded 0.5 percent lower at $19,405 a tonne and nickel was bid down 0.9 percent at $13,550 a tonne.