A surgical fastener applying apparatus includes an anvil half-section and a cartridge-receiving half-section including an elongated channel member having a pair of opposed openings defined through sidewalls thereof. A disposable assembly including a single use loading unit and a single use firing unit is configured to be releasably supported within the cartridge-receiving half-section. The disposable assembly includes a stationary housing for supporting the firing unit which includes a distal extension for supporting the single use loading unit. The stationary housing includes a pair of flared tabs configured to be releasably received within the openings of the cartridge-receiving half-section to releasably engage the disposable assembly within the cartridge-receiving half-section.