IT major Wipro Technologies and Gurgaon-based knowledge process outsourcing firm Copal Partners have expressed interest in bidding for the Indian back office business of Lehman Brothers Holdings, the US-based investment banking firm that filed for bankruptcy protection on Monday. Lehman is expected to close its captive unit in Powai, a Mumbai suburb, by the end of this month. The unit's 1,200 employees, who work on equity research and analytics support for the mergers and acquisitions business, have been orally told to quit by September-end. They have also been informed that they will be paid only for this month, which will be treated as a severance package.