Hereford and Worcester Fire and Rescue Service were called to the Hartlebury Trading Estate near Kidderminster at around 4.30pm on Sunday.
The fire involved a two-storey commercial unit, used for flat pack and distribution, was which was "severely damaged" by the fire.
No one was injured in the blaze.
A spokesman for Hereford and Worcester Fire and Rescue Service said: "We were called at 4.27pm on Sunday, April 26, to a fire in the open at Hartlebury Trading Estate.
"At its height, there were 11 fire engines on site, including crews from Wyre Forest, Droitwich, Worcester, Bromsgrove, Malvern, and Ross-on-Wye.
"The fire involved a two-storey commercial unit used for flat pack storage and distribution, which was severely damaged by fire.
"The fire was extinguished using five main jets, three hosereel jets, one compressed air foam system and two breathing apparatuses. One aerial ladder platform as also deployed.
"The incident was scaled back to one relief pump at midnight when crews damped down and turned over hot spots.
"A thermal imaging camera was used to check the premises and a reinspection arranged for 8.30am today. Police also attended and there were no casualties."
Hereford and Worcester Fire and Rescue Service group commander, Martin Lown, said: "“Good, assertive early tactics helped in fighting the fire and the compartmentalization of the building assisted in preventing any spread. Otherwise it could have been a lot worse.
“Computers were also retrieved from a two-storey office block to assist in maintaining business continuity.
“And we worked well with Severn Trent on site in redirecting our water supply to a different hydrant in order to minimize the impact on the community.”