Deerfield, Ill.-based Walgreens said Tuesday that it would spend $6.7 billion in cash and stock for a 45 percent stake in Alliance Boots, a pharmacy-led health and beauty group based in the United Kingdom.

The deal has been approved by both companies' boards of directors. The combination would create a group with more than 11,000 stores in 12 countries, and a distribution network covering more than 370 distribution centers servicing more than 170,000 customers in 21 countries.

Walgreens said it expects the deal to add to its earnings in the first year after the deal is completed. It mentioned synergies available in procurement and revenues and expects full integration to take about three years.

"We are bringing together the strengths and expertise of each company to create a worldwide healthcare platform for the future that can provide innovative ways to address global health and wellness challenges," Walgreens CEO Gregory Wasson said in a release announcing the deal. "We are looking forward to working with Alliance Boots to leverage our combined strengths and provide an even broader range of innovative, cost-effective products and services to patients and customers across the healthcare landscape."