A FIGHT by the United Democrats to continue rent controls in old buildings failed yesterday when the bill phasing out the policy was passed by 26 votes to 19. The United Democrats' attempt to win higher compensation for tenants of rent-controlled premises hit by redevelopment also failed. The bill's supporters were mainly members from the Liberal Party and some independents, such as Vincent Cheng Hoi-chuen and Simon Ip Sik-on. Meeting Point and the Association for Democracy and People's Livelihood sided with the United Democrats. The Landlord and Tenant (Consolidation) Amendment Bill will phase out rent controls by 1996 on about 33,400 premises built before 1981. It also raises the compensation from the present formula of twice the 1983 rateable value to 1.7 times the current rateable value of the premises. The failed amendment from United Democrat James To Kun-sun was opposed to lifting controls because many tenants could not afford the increases and there was not enough public housing. Another failed amendment by Mr To's colleague, Lau Chin-shek, proposed to raise the compensation for tenants from 1.7 times to twice the prevailing rateable value plus subsidies for removal. The Association for Democracy and People's Livelihood's Frederick Fung Kin-kee said: ''Premises under rent control constitute only four per cent of the total number in the private sector, so does the Government really need to scrap the policy and hence the last protection for lower income groups?'' He said rent-controlled premises would be naturally phased out by redevelopment, removal and the death of elderly tenants who comprised about 40 per cent of the total. But the Liberal Party backed the bill, with Miriam Lau Kin-yee saying rent control deprived landlords of a reasonable return. The Secretary for Home Affairs, Michael Suen Ming-yeung, said the proposals struck the best balance between the interests of landlords and tenants. He said the natural phasing out of old buildings under rent control would take a long time.