Volkswagen AG (VOW.XE) said Saturday the evaluation of possible options for an earlier takeover of Porsche Automobil Holding SE's (PAH3.XE) sportscar unit hasn't been finalized yet after a German media report suggested the auto makers identified a way to bypass a large tax payment and could push through the deal as early as August.

"The evaluation hasn't been finalized yet. As soon as we have the necessary clarity we'll inform about it in due course," Volkswagen said in a statement. The management of Volkswagen controls both Europe's largest auto maker by sales and Porsche's holding firm.

VW already owns a 49.9% stake in Porsche's core sportscar business and wants to take over the remaining 50.1% to reap more cost savings after the plan for a fully fledged merger including Porsche's holding firm had to be abandoned last year due to legal obstacles.

Porsche sold the 49.9% stake in its sports-car unit to Volkswagen in 2009 as part of a complex deal to forge a combined company after its attempt to take over its much larger rival backfired amid ballooning debt in the aftermath of the financial crisis.

At the time, Porsche and Volkswagen mutually granted each other options to transfer the remaining 50.1% stake to Volkswagen if the initial plan for a merger including Porsche's holding firm doesn't work out.

A key aspect of this alternative scenario, however, is a potential tax charge if Volkswagen and Porsche go ahead with the deal before mid-2014. Concluding the deal earlier would enable Volkswagen and Porsche to extract more cost savings faster.

Weekly Wirtschaftswoche reported earlier Saturday on its website that financial authorities in the German federal state of Baden-Wuerttemberg ruled that the deal won't trigger a tax payment of up to EUR1.5 billion if in addition to a purchase price of EUR4.5 billion Porsche's holding firm also receives one single voting share in VW. Baden-Wuerttemberg's finance ministry would view this scenario as a tax-free reorganization instead of an outright sale, according to the report. Baden-Wuerttemberg's finance ministry wasn't immediately available on Saturday.

Write to Christoph Rauwald at christoph.rauwald@dowjones.com and Philipp Grontzki at philipp.grontzki@dowjones.com