Ex-Im financing is a pretty niche market. It's subsidized loans aren't for competition against other US businesses (we leave that financing to the private market), they are for competition against foreign businesses which also enjoy much larger subsidies from their host countries.
Some interesting comments from the CEO of Delta Airlines in Congressional testimony:
In trying to justify its aircraft financing program, the Bank has made numerous inaccurate and misleading arguments. Consider its argument that its financing supports jobs here at home. Delta knows firsthand that the Bank’s statements on this front are unreliable.
The Bank has repeatedly touted two deals it financed involving Delta TechOps and the Brazilian airline GOL, asserting that these guarantees “support[] an estimated 400 jobs at Delta TechOps, according to Ex-Im Bank’s jobs-calculation methodology” – which GAO has criticized. Contrary to the Bank’s public pronouncements, however, that financing did not support, much less create, a single job at Delta TechOps. The guarantees helped GOL to issue cheap debt in 2012, ostensibly to pay the costs of a Delta TechOps contract to provide maintenance service for GOL’s narrowbody aircraft engines. The truth is that the contract was signed in 2010 and the Bank’s support arrived only after the contract had been finalized, the work was underway, and payments were being made. If the Bank is willing to publicize a deal where it is so wrong on the facts, it raises the question of what the Bank is doing in the vast majority of transactions as to which it discloses little if any information. Worse, the Bank reported to Congress that the reason it approved these two guarantees was to “overcome maturity or other limitations in private-sector financing.” That statement is misleading (if not outright false) because it implies that GOL needed help to pay its bills or that Delta would have lost the deal without the Bank’s support. In fact, the contract was signed in 2010 for a five-year term, and was being fully performed, without GOL’s needing, seeking, or receiving Ex-Im support. Although the Ex-Im guarantees were nominally related to the 2010 TechOps contract, their actual effect was to provide GOL with low-cost working capital in 2012 and beyond. The Bank’s statutory justification and motive to provide financing for a contract that was already in place, was proceeding in a normal commercial manner, and did not involve competition from a subsidized foreign competitor is not apparent to us.
He also noted that the Ex-Im financing subsidies on widebody aircraft to foreign carriers costs Americans jobs with Delta and other American carriers. This is because the Ex-Im subsidies provide foreign carriers with essentially one free jet for every eight they purchase, while Delta and other American carriers get no similar subsidy on widebody, long-haul aircraft. This necessarily results in Delta being less competitive in the marketplace and reduces employment.