Shareholders from Ecolab, Inc., and Nalco Holding Company on Wednesday approved the companies' multibillion-dollar merger, and it received antitrust clearance the following day, allowing the deal to be completed.

St. Paul-based Ecolab in July announced its plans to acquire Nalco, a Naperville, Illinois-based water-treatment provider.

Ecolab said Wednesday that the deal creates the “global leader” in water, hygiene, and energy technologies and services. It will serve more than 160 countries and have combined 2011 sales in excess of $11 billion. Ecolab is already among Minnesota's 15-largest public companies, and it reported revenue of $6.1 billion in 2010.

Ecolab said that the overall deal is valued at about $8.3 billion. More than 99 percent of its shares voted by shareholders were cast in favor of the deal, and Nalco shareholders also overwhelmingly approved the merger.

Ecolab on Thursday morning made a separate announcement, stating that it has cleared the final regulatory hurdle to complete the deal by receiving antitrust clearance from Chinese regulators.

“The completion of the merger remains subject only to customary closing conditions, and Ecolab anticipates that the parties will proceed to complete the merger effective today,” the company said in the Thursday news release.

Ecolab spokesman Michael Monahan confirmed that the company expects to complete the deal sometime Thursday.

Once the merger is completed, Erik Fyrwald, the current chairman and CEO of Nalco, will be named president of Ecolab, reporting to Baker.

“Our combined company will bring the best-in-class water and hygiene technology, enabling us to uniquely meet the growing global needs around food safety, infection prevention, water management, and energy availability,” Ecolab Chairman and CEO Doug Baker, Jr., said in a statement. “Meeting these needs is fundamental for successful societies and provides an excellent platform for us to both deliver meaningful value for our customers and provide excellent growth opportunities for our associates and shareholders.”