Major supermarket chains saw their sales fall in April from year-before levels, thanks to a legal change in pricing that took effect April 1, company officials said Monday.

Sales on a same-store basis fell 5.9 percent at Seiyu Ltd., 5 percent at Aeon Co. and 3 percent at Daiei Inc., the companies said. Ito-Yokado Co. declined to reveal a figure but suggested its sales declined in April.

The change under the revised Consumption Tax Law required retailers to display price tags that include the 5 percent consumption tax. Previously, prices on shelf signs were shown with tax excluded at most retailers.

Although there is no change in what consumers pay, critics have said the new price tags could depress consumer sentiment by giving the impression of a price hike.

"Whether the prices consumers first see are double-digit or triple-digit has a different psychological impact," an official at one supermarket chain said.