Accenture
The agency, which went public in 1999, was ranked the sixth biggest digital agency in Germany last year by the advertising news website Horizont.
SinnerSchrader has 448 employees and generated $47 million in revenue in 2016.
Accenture's offer of $9 a share values SinnerSchrader at just over $100 million. Accenture plans to offer the remaining shareholders the same share price to complete a full takeover.
In a statement emailed to Business Insider, Accenture said the acquisition would help it deepen and scale its capabilities in creating customer experiences.
Brian Whipple, head of Accenture Interactive, said in the statement:"With SinnerSchrader, we continue to build out Accenture Interactive's position as a leading digital customer experience agency."
This is Accenture Interactive's tenth acquisition since 2013 as it increasingly competes with
Consultancy firms and systems integrators are increasingly moving into advertising agency territory.
Last year, IBM bought two German agencies, ecx.io and Aperto, to help build out its growing digital agency business iX. Also in 2016, Deloitte acquired creative agency Heat.