A large increase in atomic absorption due to coherent interaction with resonant radiation is predicted for a closed transition between two degenerate atomic levels verifying 0ϽF g ϽF e (F g and F e are the total angular momentum of the ground and the excited levels, respectively͒. In good agreement with the theoretical prediction, a total absorption enhancement by a factor 1.7 was obtained on the D 2 line of 85 Rb in a vapor cell experiment.