Display Screen or Portion Thereof with Transitional Graphical User Interface

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

FIG. 2 is a front view of the second image thereof;

FIG. 3 is a front view of the third image thereof;

FIG. 4 is a front view of the fourth image thereof;

FIG. 5 is a front view of the fifth image thereof;

FIG. 6 is an enlarged detail view of the transitional graphical user interface of FIG. 1 , shown separately for clarity of illustration;

FIG. 7 is an enlarged detail view of the transitional graphical user interface of FIG. 2 , shown separately for clarity of illustration;

FIG. 8 is an enlarged detail view of the transitional graphical user interface of FIG. 3 , shown separately for clarity of illustration;

FIG. 9 is an enlarged detail view of the transitional graphical user interface of FIG. 4 , shown separately for clarity of illustration; and,

FIG. 10 is an enlarged detail view of the transitional graphical user interface of FIG. 5 , shown separately for clarity of illustration.

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

The remaining broken lines in the figures depict portions of the graphical user interface which form no part of the claimed design.