After months of delays, the U.S. Department of Justice agreed Monday to let Ecolab buy almost all of Champion Technologies, the oil and gas services firm that will give Ecolab a significant foothold in the oil services industry.

In a statement Monday, the Justice Department said it reached an agreement with Ecolab that resolves the government's anticompetitive concerns and allows the highly anticipated deal to go forward. The deal is expected to close in the next few days.

Ecolab originally announced the $2.3 billion Champion acquisition in October and said it planned to complete the deal by December. But then Ecolab had to delay the closing when Justice Department officials expressed antitrust concerns.

Under terms of the agreement, Ecolab will buy 97 percent of Houston-based Champion, which is mostly an onshore oil-and-gas additives and services company.

The remaining 3 percent of Champion's business will be sold to Clariant Corp. in North Carolina. That divested business unit helps offshore drillers and oil producers in the Gulf of Mexico maximize oil flow and provides additives that prevent pipe corrosion. It's a business that is similar to the Nalco entity Ecolab bought in December 2011 for $8.3 billion. That overlap is what initially prompted concern in Washington.

Justice Department officials said Monday that the originally proposed transaction would have "combined two of the three leading providers of production chemical management services for deepwater wells in the U.S. Gulf of Mexico."

Ecolab will pay $2.3 billion for the onshore Champion business and gain $1.3 billion in sales and about 3,200 workers in 30 countries. For a period, Ecolab, which already generates $12 billion in annual revenues, also will manufacture and license certain Champion chemicals to Clariant officials working in the Gulf of Mexico.

Ecolab CEO Doug Baker said in a statement, "We are pleased to have reached an agreement with the DOJ on this matter. We also remain very excited about the potential of this transaction."

Baker said that Champion should add 7 cents per share to Ecolab's 2013 earnings and should add 50 cents per share to earnings by 2016.

During an investor conference three weeks ago, Ecolab Chief Financial Officer Dan ­Schmechel said Ecolab should save about $160 million a year beginning in 2015 by reducing duplicative processes and costs, and by cross-selling products to Champion and Ecolab customers.

Jeff Windau, research analyst for Edward Jones, called the match "a very nice acquisition. It does compete in the Nalco business that they previously acquired. And so it does expand that and gets them into more of the energy business."

Until it bought Nalco, Ecolab was known as a cleaning and sanitation chemical company that specialized in restaurants, hotels, hospitals, factories and pest control customers. Nalco and Champion give the company its first stake in the oil and gas services business.

Ecolab shares gained 70 cents Monday to close at $80.04, near a 52-week high.

Dee DePass • 612-673-7725