The outer gravitational potential V of the level ellipsoid of revolution T is uniquely determined by two quantities: the eccentricity ε of the ellipsoid and Clairaut parameter q, proportional to the angular velocity of rotation squared and inversely proportional to the mean density of the ellipsoid. Quantities ε and q are independent, though they lie in a rather strict two-dimensional domain. It follows that Stokes coefficients I_n of Laplace series representing the outer potential of T are uniquely determined by ε and q. In this paper, we have found explicit expressions for Stokes coefficients via ε and q, as well as their asymptotics when n→ ∞. If T does not coincide with a Maclaurin ellipsoid, then | I_n| ∼ Bεⁿ/ n with a certain constant B. Let us compare this asymptotics with one of I_n for ellipsoids constrained by the only condition of increasing (even nonstrict) of oblateness from the centre to the periphery: | I_n| ∼ B¯ εⁿ/ (n²). Hence, level ellipsoids with ellipsoidal equidensites do not exist. The only exception represents Maclaurin ellipsoids. It should be recalled that we confine ourselves by ellipsoids of revolution.