COPENHAGEN, Nov 22 (Reuters) - Wind turbine maker Vestas (VWS.CO) on Monday said the cyber attack it reported at the weekend has affected parts of its internal IT infrastructure and that data has been "compromised". The incident, the financial implications of which are as yet unclear, comes as Vestas juggles record demand for green power against supply constraints and high raw material costs that are pressuring profit margins. Shares in the world"s biggest manufacturer of wind turbines, already down 25% this year before the cyber attack, dropped by about 3% in early trade on Monday. In addition to concerns over the nature of any data breach, near-term market focus will also be on production delays and related costs, including the cost of resolving the issue, Citi analysts said in a research note. The cyber security incident on Nov. 19 forced Vestas to shut down IT systems across multiple business units and locations to contain the issue, but the Danish company said it has been able to continue operations. read more The preliminary findings of its investigation into the matter also found that its customers were unaffected by the incident. "There is no indication that the incident has impacted third party operations, including customer and supply chain operations," its statement said on Monday, adding that it had started a gradual reopening of all IT systems. Vestas is already under pressure from supply chain woes but said that its manufacturing, construction and service teams had been able to continue operations despite the cyber attack. The company this month cut its 2021 outlook for a second time this year and posted forecast-lagging quarterly profit, sending its shares tumbling as much as 14%. read more