Overturning an earlier ruling that the case need not come to trial, the appeal court said that there were "a number of indications" speaking both for and against Wiedeking and Härter.
And given the high sensitivity of the case, the trial should go ahead, it said.
While the company itself is not party to the lawsuit, Porsche stood behind its former executives, maintaining that the allegations against them were "without merit".
"The company welcomes that finally these proceedings can be dealt with in court so that the accused can clear all allegations against them," said Porsche in an emailed statement.
Following long months of investigation, prosecutors had decided in December 2012 to press charges against the luxury sports car maker's CEO and CFO.
The prosecutors argue that Porsche issued at least five public statements between March and October 2008 publicly denying the plans, even though preparations for the takeover were already underway.
It was only several months later that Porsche revealed its takeover plans, sending the share price rocketing.
Porsche's bid to acquire the much-bigger VW eventually unravelled, leaving the luxury sports carmaker with more than €10 billion in debt.
The two companies then made a fresh attempt to tie the knot in 2009, with VW initially acquiring 49.9 percent in Porsche in the first stage of the complex takeover agreement, the completion of which ran into a number of legal and tax hurdles.
The lawyers of Wiedeking and Härter issued a statement, insisting that their clients were "confident that charges will prove to be totally unfounded".
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