Walgreen Co. shareholders approved the final acquisition of the European pharmacy chain Alliance Boots GmbH in a near-unanimous decision Monday. The Deerfield, Illinois, company announced that about 97 percent of shareholders cast votes in support of the plan, which will create a new holding company called Walgreens Boots Alliance Inc.

The cross-Atlantic chain will operate drugstores in all 50 states and across Europe and be the world’s largest prescription drug buyer, with trading on Nasdaq under the ticker symbol WBA expected to begin Wednesday.

“The transaction will fully combine the two companies to form the first global pharmacy-led, health and well-being enterprise,” Walgreen said in a Monday statement announcing the development.

Walgreen is the largest U.S. pharmacy chain, with 8,200 stores and fiscal 2014 sales of $76 billion. With the acquisition of U.K.-based Alliance Boots, the new company will have more than 11,000 shops spread over more than 10 countries and will have access to much of the lucrative European drug market.

Walgreens Boots Alliance Inc. will be headquartered in Deerfield, Walgreen said in the statement, reflecting its decision in August to not pursue a “tax inversion,” a controversial move that would have moved the company’s headquarters to Europe and saved the company hundreds of millions of dollars on taxes.

Tax inversions came under fire this year as a number of prominent companies considered the idea. Anger over the practice peaked in August, when Burger King Worldwide Inc. announced it was acquiring about 51 percent of Tim Hortons Inc. and moving its headquarters to Canada. In September, the Obama administration spoke out against U.S. corporations employing the tactic and the U.S. Treasury Department introduced new restrictions on its use. About 50 U.S. companies have undertaken tax inversions over the past 10 years.

The backlash against tax inversions contributed to Walgreen's decision to withdraw its plan to move its headquarters to Ireland after it acquired Alliance Boots.

Walgreen’s acquisition of its European counterpart began with the launch of a strategic partnership in June 2012 with the acquisition of 45 percent equity ownership of Alliance Boots with an option to purchase the remaining 55 percent of the company. Walgreen exercised that option in August 2014, and Monday’s development approves the final phase of the process that will see the two come together as Walgreens Boots Alliance Inc.

The announcement of the deal saw Walgreen shares rise 0.43 in Monday trading to close at $76.79. The company’s stock has risen by about a third on the year.

The move was seen as overwhelmingly positive by the vast majority of Walgreen shareholders, as shown by the near-unanimous vote Monday. But some observers, like Dieter Waizenegger, executive director of the CtW Investment Group, criticized the deal.

"Shareholders are left with too many unanswered questions about how the combined company will meet optimistic performance goals and how it will correct governance failures that became painfully obvious in the past year," Waizenegger told USA Today.