Display screen or portion thereof with transitional graphical user interface

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

FIG. 1 depicts a first appearance state in a sequence of a display screen or portion thereof with transitional graphical user interface, showing our new design;

FIG. 2 depicts a second appearance state thereof;

FIG. 3 depicts a third appearance state thereof;

FIG. 4 depicts a fourth appearance state thereof; and,

FIG. 5 depicts a fifth appearance state thereof.

The outermost broken lines illustrate a display screen or portion thereof and form no part of the design. The broken lines showing text, symbols and numerals illustrate portions of the graphical user interface and form no part of the claimed design.

The appearance of the image sequentially transitions between the images shown in FIG. 1 - 5 . The process or period in which one image transitions to another forms no part of the claim.