In antiferromagnetically coupled [Pt(5Å)∕Co(4Å)]4∕NiO(11Å)∕[Co(4Å)∕Pt(5Å)]4 multilayer with perpendicular anisotropy, net ferromagnetic stripes are created in demagnetized state between the relatively shifted domain walls in the two Co∕Pt multilayers owing to the competition between magnetostatic and exchange energies. With an external field applied antiparallel to the wall magnetization, involvement of Zeeman energy of net ferromagnetic stripes in the competition makes the net ferromagnetic stripes shrink, and the stripe width varies with field in an inversely proportional way in the low field range.