Going to trial this fall in a regional court in Hanover will be Wulff, who resigned as Germany's leader in February 2012, and film financier David Groenewold, Spiegel Online reported Tuesday.
Prosecutors first charged Wulff with bribery and corruption, but the court reduced the charges to the lesser allegation of accepting unfair advantages.
While the investigation into Wulff involved four state prosecutors, up to 24 police officers, 20,000 pages of documentation and more than 100 witnesses, the case against him was thin, Spiegel Online said.
At issue is a trip Wulff took to Munich's Oktoberfest in 2008. Prosecutors claim Groenewold paid $960 to help cover Wulff's hotel stay and child-care costs. Soon after, as governor of Lower Saxony, Wulff wrote a letter seeking support on Groenewold's behalf from Siemens for the distribution of the film "John Rabe."
Prosecutors had offered a deal to Wulff and Groenewold, but they refused.
Wulff, an ally of conservative Chancellor Angela Merkel, left office over allegations he had gotten a home loan under highly favorable terms. After leaving office, prosecutors in Lower Saxony charged him with bribery in the Oktoberfest trip with Groenewold.