  We study fluctuation-induced interaction in confined fluids above the
isotropic-lamellar transition. At an ideal continuous transition, the
disjoining pressure has the asymptotic form $\Pi(d\to\infty)\approx -C k_BT
q_0^2/d$, where $d$ is the interwall distance, $q_0$ is the wavenumber of the
scattering peak, and $C= 1/(4\pi)$ in the strong anchoring limit. The
long-rangedness is enhanced due to continuous distribution of soft modes in the
${\bf q}$-space. An unconventionally strong Casimir force with a range of
several lamella thicknesses is realistic above the transition. We also find an
oscillatory force profile near a surface-induced transition.
