12 月，美国司法部 (DOJ) 和美国联邦贸易委员会 (FTC) 发布了更新后的合并指南，该指南自 2023 年初以来一直在制定。该指南提供了这些机构在审查时将考虑的观点。交易的证据以及该证据如何具有说服力。12 月份的文件中设定的界限之一是：任何超过 30% 的合并市场份额都可能存在问题。

“对于任何潜在交易来说，这都是一种非常激进的姿态，”贝克博茨华盛顿特区办公室合伙人杰弗里·奥利弗告诉我。“自从任何法院发现合并股份为 30% 的交易存在问题以来，已经有几十年甚至更长时间了，股份几乎总是必须远高于可行的反垄断索赔。”

这并不意味着市场份额达到30%或以上的交易将被阻止；它只是表明这些机构希望交易撮合者知道他们现在担心该范围内的交易。

In December, the U.S. Department of Justice (DOJ) and U.S. Federal Trade Commission (FTC) released updated merger guidelines, which had been in the works since the beginning of 2023. The guidelines offer a view of what these agencies will consider as they examine the evidence of a deal and how that evidence may be persuasive one way or the other. One of the boundaries set in the December filing: any combined market share greater than 30% is potentially problematic.

“That’s a very aggressive posture toward any potential deal,” Jeffrey Oliver, a partner in the Washington, D.C., office of Baker Botts, told me. “It’s been decades or longer since any court has found a problem with a deal in which the combined shares are 30%, the shares almost invariably have to be much higher than that for there to be a viable antitrust claim.”

It doesn’t mean that a deal resulting in a market share of 30% or more will be blocked; it simply indicates the agencies want dealmakers to know they are now concerned about deals within that ballpark.