“A large majority of more than 90 percent of shareholders voted today to sell their shares” to Vattenfall, Nuon spokeswoman Mandy Ros told AFP.
The EU is due to rule on the deal, which will create one of Europe’s largest energy companies, later this month.
Vattenfall makes 80 percent of its sales in Sweden, Germany and Poland and produces 46 percent of its electricity from fossil fuels, 26 percent from nuclear power, 24 percent from hydroelectric power and one percent from wind.
In 2008, Vattenfall posted a net profit of 17.1 billion kronor ($ 2.0 billion), down from 19.8 billion a year earlier, on sales of 164.5 billion kronor.
Nuon, which counts more than 10,000 employees across the Netherlands, Belgium and Germany, reported sales of €6.1 billion ($8.5 billion) last year.
It is the second Dutch energy group to be bought up by a foreign firm since Germany’s RWE moved to acquire Essent for €9.3 billion.