Electronic Data Systems Corp founder Ross Perot is back in business. He has founded a new company, as yet unnamed, with some half dozen middle managers hired from EDS, and was due to announce yesterday his new company’s first contract – with the US Postal Service in Washington, which has placed prehaps the biggest order so far for the IBM 9370. The new firm will be funded by a new HWGA Limited Partnership. The embargo on Perot competing with his former firm expired this month.