The brake company was bought by British investment fund manager Doughty Hanson & Co, which also owns LM, in 2008 and was integrated into LM glassfiber to make LM Wind Power Group in 2009.
Manufacturing calliper brakes for the energy market and mining industry, Svendborg has "performed well in challenging circumstances", LM said in a statement.
Commenting on why the company chose to sell the company, LM CEO Leo Schot said: "LM Wind Power will renew its focus on the wind industry. The company has clear strategic growth plans... to secure its part in the rapidly growing offshore wind market."
Svendborg is expected to generate revenue of about EUR 62 million euros in 2013. Altra said it will finance the deal through a combination of cash and additional borrowings.