  We describe the deformed Poincare-conformal symmetries implying the
covariance of the noncommutative space obeying Snyder's algebra. Relativistic
particle models invariant under these deformed symmetries are presented. A
gauge (reparametrisation) independent derivation of
  Snyder's algebra from such models is given. The algebraic transformations
relating the deformed symmetries with the usual (undeformed) ones are provided.
Finally, an alternative form of an action yielding Snyder's algebra is
discussed where the mass of a relativistic particle gets identified with the
inverse of the noncommutativity parameter.
