The Competition and Markets Authority (CMA) has cleared the proposed merger of Marston's with Carlsberg.
The two companies will merge to create the Carlsberg Marston's Brewing Company in a deal that values Marston's at £580m and Carlsberg UK at £200m.
After investigating the deal, the CMA said that while the joint venture will mean the business will distribute each other's beer more frequently, other brewers would continue to have sufficient alternative wholesalers to deal with.
The two companies have predicted the merger will produce cost savings of £24m in its first three years.
In a statement Marston's said: "We are pleased to report that the CMA has cleared the proposed joint venture, and the antitrust condition to completion has now been satisfied."
The transaction will complete at the end of October.