The Stella Artois firm said the decline was in line with the UK industry.
The Belgian brewing giant’s overall volume sales were 1.9% up, with Stella and Beck’s combined contributing an 8.1% increase.
Inbev said its decision to “put greater focus on and investment in a fewer number of brands has produced encouraging results”.
Chief executive officer Carlos Brito said: “Our commitment to top-line growth and disciplined cost management remain key priorities for achieving sustainable long-term results.
“We believe we are equipped for the coming challenging economic environment.
“Not only has the beer business generally shown resilience in tough times, but we also operate with a lean structure with great geographic diversification between merging and developed markets.”
Inbev said the merger with Anheuser-Busch was on track for completion by the end of the year.