Alliance Boots shareholders overwhelmingly approved an 11 billion pound ($21.8 billion; 16.2 billion euros) offer from the pharmacy chain's deputy chairman and a private equity firm on Thursday.
The company expects the takeover to be complete in July, although deputy chairman Stefano Pessina and Kohlberg Kravis Roberts remain in talks with pension trustees about the funding of the pension plan.
Pessina and KKR were forced to raise their offer three times to their final bid of 1,139 pence ($22.53; 16.79 euros) per share to secure their bid for Alliance Boots after a consortium led by financier Guy Hands and Terra Firma Capital Partners launched a rival bid.
Some 96% of shareholders voted in favor of the deal, the company said.
Alliance Boots, formed last year in a combination of drug distributor Alliance Unichem and retail chain Boots Group, has around 3,000 Boots drugstores in Britain, seven other European countries and Thailand.
On the distribution side, the company supplies more than 125,000 pharmacies, health centers and hospitals.
Pessina, the executive deputy chairman of Alliance Unichem before the merger, was barred from emergency board meetings regarding the offer. He reportedly made his approach after becoming frustrated with the failure of investors and analysts to fully appreciate the value of the enlarged business.
Alliance Boots shares were barely changed, down just 0.4% at 1,128.5 pence ($22.32; 16.63 euros) on Thursday. Its last day as a publicly traded company on the London Stock Exchange will be June 25.