In this paper we study the two-body elastic scattering process in ${\varphi }^3$ theory, in the limit $s\to \infty$ with $t$ equal to or near the threshold value 4, where the mass of the scalar particle is taken to be unity. For the scattering amplitude corresponding to any ladder-type diagram, we find that there is a promotion for the power of $s$ by ½. For example, the scattering amplitude for the ladder diagram of $n+1\mathrm{}$ rungs is promoted from $O\left(s^{-1\mathrm{}}{\ln }^{n}s\right)$ away from threshold to $O\left(s^{-\frac{1}{2}}{\ln }^{n-1\mathrm{}}s\right)$ at threshold. This means that, for small coupling constants, the leading Regge pole is promoted from the neighborhood of $l=-1\mathrm{}$ away from threshold to the neighborhood of $l=-\frac{1}{2}$ at threshold. There are, in addition, infinitely many Regge trajectories approaching $l=-\frac{1}{2}$ as $t$ approaches 4. The scattering amplitude for the $n$-rung diagram is explicitly given in the limit $s\to \infty$, with $t$ at or near the threshold 4, and various scales for $t-4\mathrm{}$ are pointed out. The two-rung and three-rung diagrams are especially studied in detail.

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