Dutch retailer Royal Ahold NV, operator of U.S. supermarket chains Stop & Shop and Giant, has agreed to merge with its Belgian counterpart Delhaize Group, in a deal that creates a company that will serve more than 50 million customers a week across the Atlantic.

The two retailers announced the deal Wednesday and say it is expected to be completed in mid-2016, subject to regulators' approval. Delhaize shareholders will receive 4.75 Ahold shares for each Delhaize share. Ahold shareholders will own around 61 percent of the new company and Delhaize shareholders the rest.

The two retailers had combined sales last year of 54.1 billion euros ($60.6 billion).

Delhaize, which owns supermarkets throughout Belgium, also operates the Hannaford and Food Lion stores in the eastern United States.