The magazine said the German Finance Ministry already has a draft for the deal available. Volkswagen will have to pay 3.9 billion euros (3.2 billion pounds) plus taxes for the remaining stake.
Instead of an anticipated 1 billion euros, Volkswagen will have to pay a low three-digit million amount in taxes, Der Spiegel said. In total the acquisition will cost Volskwagen a little over 8 billion euros.
Volkswagen acquired 49.9 percent of Porsche sports cars for 3.9 billion euros in December 2009 as part of a deal that prevented the likely insolvency of debt-laden parent Porsche SE.
Volkswagen declined to comment. In principle we don't say anything about the agenda of our institutes, a spokesman said.
According to disclosures from Volkswagen, Porsche SE has a put option to sell its 50.1 percent exercisable from November 15, while Volkswagen can exercise its call option between March and April of next year.
Last week Volkswagen said the company was closely examining other possible methods apart from the put-call options that would allow for an integration of Porsche within VW as soon as possible.
(Reporting by Harro ten Wolde; Additional reporting by Jan Schwartz; Editing by Sophie Walker)