Sun Microsystems Inc has carved out a leading position in the financial services business, with many dealers and brokers having Sun workstations rather than personal computers on their desks, and the business makes up about 10% of its turnover. Now the company is well on the way to winning a similar lock on central computers for the nascent home banking business. On Friday, the Visa Interactive arm of the Visa International Bank Ass-ociation in Herndon, Virginia announced that it would use Sun computers for a range of home banking services being planned for US banks. The company already has a similar relationship with the Interactive Transaction Processing joint venture of Electronic Data Systems Corp, France Telecom and US West Inc to provide electronic bill-paying and transaction delivery for the emerging home banking market. Sun admits that it has a third such deal, as yet unannounced, and the New York Times hears that it is with the other of the credit card Big Two, MasterCard International. Visa Interactive says it has signed on 30 banks across the US, but so far only two have announced their plans to use the Visa home banking system, Bank IV and NationsBank. Sun says it also has a similar agreement with Intuit Inc, but that deal hasn’t been announced.