Let r, h ∈ N with r ≥ 7 and let F(x, y) ∈ Z[x, y] be a binary form such that F(x, y) = (αx + βy) r − (γx + δy) r , where α, β, γ and δ are algebraic constants with αδ − βγ 0. We establish upper bounds for the number of primitive solutions to the Thue inequality 0 < |F(x, y)| ≤ h, improving an earlier result of Siegel and of Akhtari, Saradha & Sharma. uv = (αx + βy)(γx + δy) = χ(Ax 2 + Bxy + Cy 2 )