Krishna Prasad Sitaula, Nepal's home minister, said the Nepalese government and UDMF had signed an agreement on Thursday, bringing an end to the two-week strike.
The UDMF and Nepalese government also agreed on greater autonomy for the southern plains of Nepal, known as the Terai region, following the forthcoming polls.
Rajenda Mahato, UDMF leader said: "In this country, we have to struggle for our rights, time and again. This time we did the same so as to have a good and valid constituent assembly election."
Girija Prasad Koirala, Nepal's prime minister told journalists that he hoped the April elections would address the issues of all marginalised groups.
Koirala said: "Let there be no more differences between us. The constituent assembly elections will find solutions to all the problems that Nepal faces."
Nepal's former rebel Maoists and major political parties have all registered for the April assembly polls to elect a new constituent assembly, hoping to rewrite the Nepalese constitution and end the 239-year-old monarchy.
The body elected to rewrite the Nepalese constitution will formally end the world's last Hindu monarchy run by King Gyanendra.
Gyanendra was forced to end an authoritarian period of direct rule in April 2006, following mass protests.