The global garment industry would have to spend about $3 billion over five years to bring safety standards at Bangladesh apparel factories to Western standards, an analysis by a labor-rights group shows.

The analysis, provided to Bloomberg News by the Worker Rights Consortium, comes after a fire at a factory that made garments for Wal-Mart Stores Inc. and Sears Holdings Corp. killed more than 100 people last month. Upgrades to the country’s approximately 4,500 factories would cost the garment industry about 10 cents per garment, the group said.

The Washington-based group estimates are based on discussions with U.S. fire safety experts and on estimates of local construction costs in Bangladesh, said Scott Nova, the group’s executive director. Nova said the figures are “high-end estimates” because the group assumed that all factories need improvements that include fire exits and alarms, emergency lighting and training programs.

Since the blaze at Tazreen Design Ltd. factory on Nov. 24, Western companies have faced increased calls from labor-rights organizations to pay suppliers higher prices so factory owners can afford safety upgrades.

At a 2011 meeting convened to find ways to boost safety at Bangladesh garment factories, Wal-Mart declined to pay suppliers more to help them upgrade their manufacturing facilities because doing so would be too costly.

Kevin Gardner, a Wal-Mart spokesman, didn’t immediately reply to an e-mail requesting comment.