The party, led by Pushpa Kamal Dahal aka Prachanda, is now being broken by its former senior leader and former prime minister Baburam Bhattarai.
Bhattarai, who departed from the party in September voicing displeasure over the new constitution the party chose, is now preparing to form a new political party akin to the Aam Aadmi Party of India.
He said his new party will be socialist in nature and not a hardcore communist outfit.
A total 45 Maoist central committee, standing committee and politburo members close to Bhattari on Tuesday furnished their resignations to join the proposed party to be formed by Bhattarai.
A meeting of these leaders held at Bhattarai's residence decided to quit the Maoist party, said party leader Ram Rijan Yadav. "We have also given up the party membership."
In 2009, a faction under Matrika Yadav split from UCPN-Maoist. In 2012, the party suffered a split that was led by veteran communist leader, Mohan Bidhaya Kiran.
Later, the party again split in 2014. This time a long-time aide of Prachanda, Netra Bikram Chand, formed a new communist party.
Now, Bhattarai, who completed his PhD from New Delhi's Jawaharlal Nehru University in regional development and planning, has walked out.
Party leaders say new party will be formed within one and a half month.
Prachanda's UPCN-Maoist is in the government led by the Communist Party of Nepal-Unified Marxist Leninist.