State-owned Odisha State Road Tranport Corporation (OSRTC) would operate the buses in four LWE-hit districts under Biju Gaon Gadi Yojana (BGGY), its CMD Sanjeev Marik said.
The buses would be flagged off by Chief Minister Naveen Patnaik on December 31, he said.
"The buses would ply on 28 routes in Sundargarh, Deogarh, Nuapada and Gajapati districts," Marik said, adding that the fleet would add to the 57 already plying buses in other LWE-hit districts of the state.
Under the BGGY scheme, Rs 21 crore was earmarked to launch 100 buses during 2015-16 fiscal, Marik said.
Earlier, 40-seater buses had been introduced in Rayagada, Nabarangpur, Malkangiri, Kandhamal, Brahmapur, Koraput, Ganjam and Kandhamal districts under the scheme, an OSRTC official said.