T-Mobile USA says it’s planning to hire more than 100 new full-time employees in Maine by the end of the year. The jobs include customer service and sales representatives who will be located at the T-Mobile call center in Oakland. T-Mobile spokeswoman Patty Raz said the workforce expansion is necessary because of increased call volumes. The company is holding a job fair on Thursday at the call center. Raz said the call center now has more than 400 employees.