(BLOOMBERG) - For years, women have had a foot in the door to the finance industry by becoming bank tellers. Now that path is disappearing due to the increase in e-banking. The number of tellers - a job in which four out of five positions are held by women - has dropped more than 20 per cent in the United States and Canada in the past decade as transactions move from branches to mobile phones. Technological advances are eliminating the need for bank tellers, threatening an entry point for women in the male-dominated industry which has sought to promote more females to leadership roles. While the climb remains steep, some financial firms have managed to improve the gender balance in their executive ranks. "I wouldn't have been a banker without it," said former Wells Fargo chair Betsy Duke, who started as a teller. Women hold 51 per cent of entry-level positions and 38 per cent of senior management jobs in the banking and consumer finance industry in the US. "When you already have a workforce that has a lot of women, there are more opportunities for women's leadership," said University of Toronto's Professor Sarah Kaplan, who is director of the Institute for Gender and the Economy. T...