The figure reported by several German dailies is considerably more than the 10,000 job losses anticipated by the German trade union IG Metall as part of a broad revamp of the company's operations.
A total of 17,200 posts are expected to be cut from the industrial giant's workforce of 400,000, including 6,400 in Germany alone, according to the Suddeutsche Zeitung.
The scale of the cuts, which are expected to mainly affect administrative positions, is unprecedented in the 160-year history of the German company, which manufactures products from light bulbs to power stations and trains in some 190 countries.
The German cuts would be spread over two years and are due to be announced officially in the autumn, the Suddeutsche Zeitung said.
No Siemens spokesman was immediately available for comment on the reports. A meeting between management and unions is due at the beginning of next month.
The company's Austrian chief executive Peter Loescher said on Thursday it would try to avoid forced redundancies.
"We will try and make this as socially acceptable as possible," Loescher told the daily Die Welt.
Loescher has already announced that Siemens will seek to cut 1.2 billion euros (1.9 billion dollars) from administrative costs by 2010 and implied that posts would be eliminated.
The German conglomerate is carrying out a broad revamp of its operations and already announced 3,800 jobs cuts at its SEN telecommunications systems unit and 1,000 posts at Osram, its lighting systems division.