GENERALE DE BANQUE, HELLER BUY FACTORING UNIT Generale de Banque SA <GENB.BR> and <Heller Overseas Corp> of Chicago have each taken 50 pct stakes in factoring company SA Belgo-Factors, Generale de Banque said in a statement. It gave no financial details of the transaction. SA Belgo-Factors' turnover in 1986 was 17.5 billion Belgian francs.