A federal judge in Washington, juggling challenges to two multibillion-dollar merger deals in the health insurance industry, said Thursday he would keep only one of the cases and begin the trial in the other ahead of the U.S. Justice Department’s preferred February start date.

U.S. District Judge John Bates gave no indication of which case he would preside over, and he did not specify exactly when he wanted a trial to begin. Bates did, however, flag his representation of Blue Cross Blue Shield two decades ago, noting that it could create the appearance of a conflict of interest in the Justice Department’s case against Anthem Inc.’s proposed $54 billion acquisition of Cigna Corp.

Aetna Inc., under deadline pressure in its proposed $37 billion acquisition of Humana Inc., faces a year-end deadline to wrap up the deal. Anthem, citing an April 30 deadline to close its tie-up with Cigna, also wants resolution by the end of 2016.