BERLIN, May 17 (Reuters) - German prosecutors are formally investigating Porsche SE PSHG_p.DE executives Matthias Mueller and Hans Dieter Poetsch to determine whether they manipulated markets by delaying the disclosure of information pertaining to Volkswagen's (VW) emissions scandal.

The prosecutor's office in Stuttgart said on Wednesday it was investigating Porsche SE executive board member Mueller, who is also the chief executive of Volkswagen VOWG_p.DE , and Porsche SE CEO Poetsch, who is also VW's chairman, on suspicion they may have informed investors too late about financial risks to the Porsche holding firm from Volkswagen's VOWG_p.DE emissions scandal.

The inquiry, which also targets former VW CEO Martin Winterkorn and has been running since February, is similar to one launched by prosecutors last year in Braunschweig, near VW's Wolfsburg headquarters, into current and former VW board members over whether they delayed the release of information about the cheating of diesel emissions tests.

Porsche SE said the allegations were unfounded, adding it had complied with disclosure rules. The family-owned holding company is headquartered in Stuttgart and controls 52.2 percent of VW's voting shares.

Prosecutors said the investigation was prompted by a complaint from markets regulator BaFin in the summer of 2016, the same time at which Braunschweig prosecutors launched their probe into VW officials.

(Reporting by Andreas Cremer; Editing by Edward Taylor and Maria Sheahan) ((Andreas.Cremer@thomsonreuters.com; +49-30-2888-5084; Reuters Messaging: andreas.cremer.thomsonreuters.com@reuters.net))