Display Screen or Portion Thereof with Transitional Graphical User Interface

FIG. 1 is a first image in a sequence for a display screen or portion thereof with transitional graphical user interface showing our new design, according to a first embodiment;

FIG. 2 is a second image thereof;

FIG. 3 is a third image thereof;

FIG. 4 is a fourth image thereof;

FIG. 5 is an enlarged view of the icon on the lower right side of the display screen of FIG. 1 ;

FIG. 6 is an enlarged view of the icon on the lower right side of the display screen of FIG. 2 ;

FIG. 7 is an enlarged view of the icon on the lower right side of the display screen of FIG. 3 ; and,

FIG. 8 is an enlarged view of the icon on the lower right side of the display screen of FIG. 4 .

The outermost even-dash broken lines illustrating portions of a display screen or portion thereof form no part of the claimed design. The remainder of the even-dash broken lines illustrating portions of the transitional graphical user interface forms no part of the claimed design.

The appearance of the transitional graphical user interface sequentially transitions between the images shown in FIGS. 1 - 4 . The process or period in which one image transitions to another image forms no part of the claimed design.