26 CFR § 1.404(c)-1 - Certain negotiated plans; effect of section 404(c).
(1) The contributions under the plan are held in trust for the purpose of paying, either from principal or income or both, for the benefit of employees and their families, at least medical or hospital care, and pensions on retirement or death of employees; and
(2) Such plan was established before January 1, 1954, as a result of an agreement between employee representatives and the Government of the United States during a period of Government operation, under seizure powers, of a major part of the productive facilities of the industry in which such employer is engaged.
(b) The term “as a result of an agreement” is intended primarily to cover a trust established under the terms of an agreement referred to in paragraph (a)(2) of this section. It will also include a trust established under a plan of an employer, or group of employers, who are in competition with the employers whose facilities were seized by reason of producing the same commodity, and who would therefore be expected to establish such a trust as a reasonable measure to maintain a sound position in the labor market producing the commodity. Thus, for example, if a trust was established under such an agreement in the bituminous coal industry, a similar trust established about the same time in the anthracite coal industry would be covered by this provision.
(c) If any such trust becomes qualified for exemption under section 501(a), the deductibility of contributions by an employer to such trust on or after the date of such qualification would no longer be governed by section 404(c), even though the trust may later lose its exemption under section 501(a).