Siemens makes products ranging from power stations to high-speed trains and medical imaging equipment.
The roughly 30,000-square-metre (320,000-square-foot) premises in the Bavarian capital had until now housed Siemens commercial department for southern Germany which recently moved to new offices.
City and local authority officials visited the site last Friday, the spokesman said.
A decision was expected in coming days on when and how many refugees can be accommodated there, he added.
Germany this year expects some 200,000 asylum seekers to cross its borders -- nearly 60 percent more than in 2013 when numbers had already soared by almost two-thirds.
The leading country of origin is Syria, where over three years of bloody fighting have driven more than three million people to flee, mostly to Turkey, Lebanon, Jordan and Iraq.
Across Germany, former army barracks have been requisitioned, and tents and mobile homes set up to house refugees.