TORONTO — Alliance Communications Corp. said Wednesday that its distribution agreement with New Line Cinema has been extended into 2000.Time Warner’s New Line subsidiary is one of Alliance’s most important distribution partners. The Toronto-based company reps all New Line and Fine Line product, in all media, in Canada. Industry analysts have fretted for more than a year about the future of Alliance’s relationship with New Line, fearing Time Warner would absorb New Line’s product into its own Canadian distribution infrastructure. But Alliance has done a good job promoting New Line’s films in Canada in the past and, analysts said, made a renewal offer that was too good to refuse. Terms were not disclosed and Alliance declined to comment.