OSLO (Reuters) - Norway's $850-billion sovereign wealth fund, the world's largest, has filed a complaint against Volkswagen <VOWG_p.DE>, as part of a joint legal action following the carmaker's emissions scandal, the fund said in a statement on Friday.

The fund said the complaint was filed to the Braunschweig District Court in Germany and is part of the lawsuit filed by law firm Quinn Emanuel on behalf of institutional funds in connection with the scandal..

It is Volkswagen's largest shareholder without a seat on its supervisory board and said in May it planned to join class-action lawsuits filed against Volkswagen over the German automaker's emissions scandal.

The fund, which holds 1.02 percent of VW, has long been critical of Volkswagen's governing structure, where the Porsche and Piech families hold 31.5 percent of the capital but control 50.7 percent of voting rights.

In the past, it said it had written to Volkswagen about its concerns over the company’s leadership structure.

Separately, the fund voted against every proposal to discharge the members of the board of Volkswagen for their activities in 2015 at the firm's annual general meeting on June 22, according to voting records published on its website.

It also voted in favor of a shareholder proposal to approve a special audit of how Volkswagen's management and board handled the emissions scandal.

(Reporting by Stine Jacobsen, editing by Gwladys Fouche and Jane Merriman)