About Experience letter and Relieving letter

Hi I am working in A company close to an year due to company work culture and work i decided to join the another company ..but my present company notice period is 90 days they are not ready to reduce it nor ready to give buy out option ..what are major reasons that i can give them to reduce the notice period and get it easily relived within 30 days and also if i abscond how i can approach them to get experience letter and relieving letter..if i abscond there will be a career gap about an year how do i explain to my new employer if I join the new company will they come to know about my previous employment history through UAN number? I Have recently attend one of the company interview which is MNC company,(profile and salary company reputation all is good), where they ask me to join with 30 days since i have not shown my present company details(currently working) .if i get abscond will they come to know about my immediate previous employment history and terminate it.?how can i get my relieving letter or experience letter smoothly..if i tell them i have got offer in other organization i donot think so they will relieve me in 30 days..