In a study published this year, Ms. de Rugy and a co-author, Diane Katz, looked at the largest buyers of exports supported by Export-Import Bank financing and found that the top 10 were all either foreign oil companies or airlines. The authors singled out the subsidies to foreign oil companies: “The federal government,” the report said, “doubly disadvantages U.S. energy firms — through Washington’s excessive regulation and Ex-Im Bank subsidies to U.S. firms’ foreign competitors.”

The Mercatus Center is listed as one of the projects of the Koch family foundations. Charles G. and David H. Koch, libertarian conservative philanthropists, are also the chief executive and executive vice president of the privately owned Koch Industries, which has substantial oil and energy interests. Another Koch-backed group, Heritage Action for America, is an opponent of the Export-Import Bank.

G.E. says that in 27 countries, particularly those in the developing world, backing from an export credit agency is often a requirement on bid proposals to sell the industrial equipment G.E. makes. “It’s not a choice G.E. makes,” said John G. Rice, G.E.’s vice chairman for global operations.

In an interview, Mr. Rice said G.E.’s decisions about plant locations were made on a case-by-case basis. In the last seven years, for example, G.E. has invested $2 billion in seven new jet engine plants in America, including in Dayton, Ohio, and West Lafayette, Ind. Any suggestion that the Waukesha decision means G.E. is turning away from manufacturing in the United States “makes no sense,” Mr. Rice said.

No ground has been broken and no site has been selected for the new Canadian factory. If financing for the Export-Import Bank is quickly restored, will the Waukesha plant and its workers be spared?

No, Mr. Rice said, the decision is irreversible. An extension of Export-Import Bank funding, he said, would not remove the business risk that the bank might be killed a few years later.

The enthusiastic backing of Canada’s export credit agency, he said, was a “very important consideration” in deciding to locate a new factory there. But there were other considerations as well, he said.