UPDATE 3-Ecolab to buy Champion Technologies for $2.2 bln

(Adds details)

Oct 12 (Reuters) - Cleaning services company Ecolab Inc

will buy privately held oilfield specialty chemicals maker Champion Technologies Inc for about $2.2 billion to tap into rising demand for products used in oil and natural gas drilling.

St. Paul, Minnesota-based Ecolab will pay about $1.7 billion in cash and issue about 8 million shares to Champion, subject to certain adjustments at and after closing. Ecolab's shares closed at $63.67 on the New York Stock Exchange on Thursday.

Ecolab said Champion's global footprint and its products, used in pipelines, hydraulic fracturing and refinery boilers, would help it expand internationally.

"Champion's technology and product strengths in the U.S. and Canada are very complementary to our innovative technology and services in the offshore and international energy markets," Ecolab CEO Douglas Baker said in a statement.

Ecolab, whose technologies, chemicals and services are used in water treatment, pollution control, energy conservation and the oil industry, bought Nalco Holding Co last year for $5.4 billion to build up its business that treats water for the oil drilling and food production industries.

Houston-based Champion, whose competitors include Schlumberger NV , Halliburton Co and Baker Hughes Inc , had sales of $1.2 billion last year, Ecolab said.

Two entities associated with Microsoft founder Bill Gates owned 10.7 percent of Ecolab as of June 30.

Ecolab said in May it would allow them to raise their combined stake to 25 percent.

Ecolab promotes its environmental credentials, saying it uses the least amount of energy and water and generates less waste in the use of its products and services for the cleaning of hotels, restaurants, food plants and oil rigs.

(Reporting by Krishna N Das; Editing by Ted Kerr)

((krishna.das@thomsonreuters.com)(within U.S. +1 646 223 8780)(outside U.S. +91 80 4135 5800)(Reuters Messaging: sakthi.prasad.thomsonreuters.com@reuters.net))