Kumar had in the past said that his party would extend support in 2014 Parliamentary elections whoever supported Bihar's demand for the special category status.
The Raghuram Rajan Committee report, which puts Bihar among 10 least developed states is being seen as the Congress reaching out to JD(U).
Incidentally, the JD(U) has severed its 17-year-long alliance with BJP in June over the elevation of Narendra Modi as the party's poll panel chief.
The Bihar CM said the revisiting of criteria for declaring backwardness as carried by the sub-committee headed by Raghuram Rajan would "open all doors for future economic assistance".
However, it would have been better if the panel had taken per capita income as criteria for deciding economic backwardness of the states instead of per capita consumption, the CM said.
"But, still even this form of the report is also welcomed," he said and added that he had thanked Union Finance Minister P Chidambaram for the 'positive' report.