The UK's competition watchdog, the Competition and Markets Authority (CMA), has launched a formal investigation into Carlsberg's £3.3bn takeover of Britvic.
The CMA has set a deadline of 18 December for the first phase of the investigation.
Carlsberg has stated that the deal would create a beverage "powerhouse" by combining Britvic's soft drinks products with Carlsberg's beer offering.
The CMA will decide after the initial investigation whether to conduct an in-depth phase 2 investigation or approve the deal.