Fair Isaac shares fell 7% in extended trading Thursday and TransUnion dropped 6% after Bloomberg reported that the Federal Housing Finance Agency is considering requiring lenders to use credit data from two major bureaus instead of the traditional three for mortgages backed by Fannie Mae and Freddie Mac. The agency has not announced an official schedule, while FHFA Director Bill Pulte is scheduled to appear at a mortgage industry conference in Chicago on Oct. 12 and may unveil the change then. The potential bi-merge system would reduce demand for traditional tri-merge reports and add pressure to FICO as VantageScore gains acceptance in government-backed mortgage underwriting. FICO shares already plunged nearly 49% in September after FHFA approved VantageScore as an acceptable mortgage credit-scoring model, ending FICO's decades-long position as the sole accepted system in that market. Bank of America analysts downgraded Fair Isaac earlier this week, citing weakening mortgage-sector pricing strength. Fair Isaac shares are down almost 65% year to date, while the company continues to generate subscription revenue from decisioning software across sectors and carries substantial debt obligations.