A Danish businessman is in the lead to become mayor of Rostock and become the first non-German citizen to head a large city in Germany.

The German news agency dpa reported Monday that 46-year-old Claus Ruhe Madsen received 34.6% in the first round of voting for the mayor's post in the northeastern Baltic coast city on Sunday.

His closest challenger, Left party candidate Steffen Bockhahn, received 18.9%.

Ruhe Madsen isn't affiliated with a political party but had the support of the center-right Christian Democrats and pro-business Free Democrats.

The two leading candidates will face a runoff vote on June 16.