Volkswagen AG is being sued for 3.3 billion euros ($3.7 billion) over the cover-up of its polluting diesel engines, its biggest legal challenge in Germany after a wave of lawsuits in the U.S. centered on the scandal.

The action was filed Monday at the Braunschweig Regional Court on behalf of 278 institutional investors from around the world, lawyer Andreas Tilp said by telephone. The suit claims VW failed to publish information about the emissions scandal in a timely manner, he said.

As “Volkswagen persistently denies any settlement negotiations and also refuses to waive the statute-of-limitation defense until now, it was necessary to file this,” Tilp said.

The case comes almost six months after Volkswagen admitted it installed software in its diesel vehicles to cheat emissions testing, a scandal that’s rippled through the global car industry. So far, 65 cases are pending in Braunschweig over the issue, the court said last week. The company also faces a multitude of lawsuits in the U.S. as well as criminal probes in various countries.

“We don’t know the suit yet and can’t comment further,” VW spokesman Eric Felber said.

Tilp has represented investors in many German cases over capital-market disclosure issues. His firm represents institutional investors suing Porsche SE for a combined 2.6 billion euros.

Among the plaintiffs in the new VW case are investors from Australia, Austria, Canada, Denmark, France, Italy, Japan, Luxembourg, the Netherlands, Norway, Sweden, Switzerland, the U.K., the U.S. and Taiwan. These groups include 17 German investment management companies as well as insurance companies and CalPERS, the California Public Employees’ Retirement System, one of the largest pension funds in the U.S., Tilp said.

The lawsuit is being financed by Claims Funding Europe, DRRT, Grant & Eisenhofer and Kessler Topaz Meltzer & Check LLP. Another 20 institutional investors with damage claims of more than 1 billion euros are in talks with the firm about an additional suit, Tilp said.

Tilp filed the first individual shareholder case against VW on Oct. 1. The lawyer has asked the court to open test-case proceedings. If the request is granted, all capital-market cases will be jointly heard in a special procedure before the Braunschweig Higher Regional Court in the German state of Lower Saxony.