Display Screen or Portion Thereof with Transitional Graphical User Interface

FIG. 1 is a front view of a first image of a display screen or portion thereof with transitional graphical user interface.

FIG. 2 is a front view of a second image of the display screen or portion thereof with transitional graphical user interface.

FIG. 3 is a front view of a third image of the display screen or portion thereof with transitional graphical user interface.

FIG. 4 is a front view of a fourth image of the display screen or portion thereof with transitional graphical user interface.

FIG. 5 is a front view of a fifth image of the display screen or portion thereof with transitional graphical user interface.

FIG. 6 is a front view of a sixth image of the display screen or portion thereof with transitional graphical user interface.

FIG. 7 is a front view of a seventh image of the display screen or portion thereof with transitional graphical user interface; and,

FIG. 8 is a front view of an eighth image of the display screen or portion thereof with transitional graphical user interface.

The outermost broken lines in the figures show a display screen or portion thereof, and form no part of the claimed design.

The appearance of the transitional image sequentially transitions between the images shown in FIGS. 1 - 8 . The process or period in which one image transitions to another image forms no part of the claimed design.