DEERFIELD, Ill. — Walgreen Co. continues to move ahead with its planned acquisition of Alliance Boots GmbH.

The company has filed documents with the Securities and Exchange Commission for the creation of a new holding company, Walgreens Boots Alliance Inc., which will be legally based in Delaware.

Deerfield, Ill.-based Walgreen Co. and Bern, Switzerland-based Alliance Boots will become wholly owned subsidiaries of the new holding company.

The filing also informs shareholders that a special meeting will be held in which they will vote on whether Walgreens should complete the purchase of the remaining 55% of Alliance Boots and proceed with the reorganization into the Walgreens Boots Alliance holding company.

Walgreens also has announced the appointment of activist investor Barry Rosenstein to its board of directors. A second director, to be named soon, also is slated to be added to the board.

“We are pleased to welcome Barry to the board in this pivotal moment for our company as we anticipate the completion of the Walgreens-Alliance Boots merger, establish an efficient global platform for pharmacy-led health and well-being, and launch a new generation of growth and value creation,” said Walgreens chairman James Skinner. “We look forward to the experience and new perspectives he will bring to the board and company as we launch Walgreens Boots Alliance Inc.”

Rosenstein is the founder and managing partner of New York-based Jana Partners LLC, a hedge fund with more than $11 billion in investments and commitments.

In connection with the appointment, Walgreens will name an additional independent director recommended by Jana and agreed to by Walgreens. In addition, any replacement directors named to fill board vacancies will need to be mutually agreed upon by Walgreens and Jana.