The families that own Porsche are close to a compromise agreement that could defuse the power struggle over control of the German carmaking powerhouse they seek to forge, sources close to the transaction told Reuters on Friday.

They are getting closer, one of the sources said.

The compromise model, now supported by Porsche Chairman Wolfgang Porsche, envisions VW absorbing Porsche's healthy sports car business, Porsche AG, as VW Chairman Ferdinand Piech has been proposing, another source said.

VW would initially get just under half of Porsche AG, while holding company Porsche SE would remain entirely controlled by the Porsche and Piech families under the plan that has been approved in principle by the families, the sources added.

Qatar would take over derivative contracts owned by Porsche that would give the Gulf state a 20 percent stake in Volkswagen, Europe's biggest carmaker, the sources said.

A deal along these lines would undercut Porsche Chief Executive Wendelin Wiedeking, who on Thursday evening had to deny speculation that he was about to leave the group.

German magazine Der Spiegel reported that Porsche's owners had already agreed to replace him as head of the sports car business with production chief Michael Macht. The magazine said it remained open who would succeed Wiedeking as Porsche SE head.

Porsche shares fell 1.4 percent and Volkswagen stock eased 0.4 percent by 1350 GMT (9:50 a.m. EDT), lagging a 1.1 percent gain in the DJ Stoxx European car sector index.

Porsche said it was unaware of plans to replace Wiedeking. VW declined comment.

AUTOMOTIVE EMPIRE

Piech, a co-owner of Porsche, has been pushing to buy Porsche AG as a way to add a 10th brand to his sprawling automotive empire that ranges from tiny VW models to high-end Bugattis and Lamborghinis to heavy trucks.

Piech's cousin Wolfgang Porsche and Wiedeking had fought such a sale.

The boards of both companies meet separately in Porsche's home town of Stuttgart on July 23.

Porsche had to abandon plans to take full control of its much larger peer as its debt mounted -- sources told Reuters on Wednesday its net debt has surpassed 10 billion euros ($14.11 billion) -- just as global car markets collapsed.

That left Porsche with a 51 percent stake in VW, which agreed on May 6 to enter talks on creating an integrated car group.

Porsche, whose Porsche AG unit makes the famed 911 sports car, has been in talks for weeks with Qatar about selling a minority stake or a package of options that control 20 percent of VW shares.

(Reporting by Philipp Halstrick and Jan Schwartz; Editing by Michael Shields)