Abstract Field induced diamagnetic fluctuations have been studied ∗ ∗ This work has been supported by CICYT (Mat91-0742) and MIDAS (Mat93-2331). in a melt textured ceramic with composition YBa 2Cu 3O 6.6 having 20% of Y 2BaCuO 5 precipitates and Tc∼53K. The characteristic field-independent temperature-magnetization crossing point M ∗(T ∗) has been observed indicating that fluctuation effects are important near the mean field H c2(T) line. A 2D scaling of the reversible magnetization has been found to be clearly superior to 3D scaling, contrary to fully oxygenated YBa 2Cu 3O 7. This high field magnetization is also found to be in excellent agreement with the theoretical predictions of 2D typeII superconducting systems.