At an extraordinary general meeting, the shareholders gave their approval for the deal, which would make Lenovo the world's third-largest PC maker, from being the eighth largest PC maker in the world.
In a $1.75 billion deal signed in December 2004, IBM had sold off its PC business to Lenovo.
Chinese firm buys IBM's PC business
About 57 per cent of Beijing-based Lenovo's equity is held by Legend Holdings Ltd., controlled by the Chinese government.
IBM earned a net profit of about $100 million on global sales of $9 billion from the personal computer business.
With this acquisition, Lenovo will have annual revenue of more than $12 billion and will move its headquarters from Beijing to New York.