MUNICH, Sept 21 (Reuters) - Siemens will decide within days whether to continue negotiations on a potential rail combination with either Canadian group Bombardier or with French peer Alstom, a person close to the matter said.

In a potential deal with Alstom, Siemens would transfer its rail operations to Alstom and become majority shareholder of Alstom, the source added. (Reporting by Alexander Hübner; Writing by Arno Schuetze; Editing by Maria Sheahan)