In a move aimed at conserving energy, MOS Food Services Inc. announced Thursday that it will stop giving customers plastic bags to carry their purchases in by July 1, saving an estimated 352 kiloliters of petroleum annually.

It is the first major hamburger chain here to completely stop dispensing plastic bags, according to company officials.

MOS Food will replace the plastic bags with unbleached paper ones, which were introduced on a trial basis at some shops last August. The paper bags cost more than the plastic ones, but the company says it is curbing costs by limiting use of the bags.

As part of an environmental drive, the company will also propose that customers purchase specially designed unbleached, undyed cotton bags for repeated use. The cloth bags will go on sale in July at MOS Burger outlets and cost 700 yen each.