The paper said such a request would have to be approved by the U.S. Department of Justice as well as a German court.

Schmidt was sentenced on Wednesday to seven years in prison and fined $400,000 (298,886.7 pounds), the maximum possible under a plea deal the German national made with prosecutors in August after admitting to charges of conspiring to mislead U.S regulators and violate clean-air laws.

Schmidt read a written statement in court acknowledging his guilt.

Welt am Sonntag quoted Schmidt's lawyer Alexander Saettele as saying that he was looking into a possible appeal but that no decision had been made yet.

The verdict "was not a surprise, but it was still disappointing to him that he was not able to get through to the judge," Saettele told the paper.

Saettele of Berlin-based lawfirm Danckert Huber Baerlein was not immediately available for comment outside his firm's office hours.

David DuMouchel, a Detroit-based lawyer for Schmidt of lawfirm Butzel Long, declined to provide any details on the case.

"There are a number of matters that remain to be done and so the matter is still active and therefore I cannot comment," he said in an e-mailed statement.

Schmidt also still faces possible disciplinary action at Volkswagen, including damages claims and termination of his contract, according to a company spokesman.

"That is an integral part of the compliance guidelines of any company," the spokesman told Reuters on Friday.

In March, Volkswagen pleaded guilty to three felony counts under a plea agreement to resolve U.S. charges that it installed secret software in vehicles in order to elude emissions tests.

Schmidt was in charge of the company's environmental and engineering office in Auburn Hills, Michigan, until February 2015, where he oversaw emissions issues.

U.S. prosecutors have charged eight current and former Volkswagen executives.

(Reporting by Maria Sheahan; Additional reporting by Jan Schwartz; Editing by Elaine Hardcastle)