The characterization of passive component properties over a wide frequency range is usually done using scattering parameters. This paper presents the measurement and modeling approach for two typical three-phase mains chokes (3x100µH, 230V, 60A and 3x2.3mH, 230V, 65A) based on six-port scattering parameters using a common two-port vector network analyzer. The model allows to reproduce consistently common-mode and differential-mode response of a passive six-port device, covering a frequency range from 10Hz to 300MHz.