A U.S. court on Tuesday asked Valeant Pharmaceuticals International Inc (VRX.TO) and activist investor Bill Ackman's Pershing Square (PSHZF.PK) to appear for a hearing to discuss the proposed settlement in an insider trading lawsuit.

The hearing, set for Jan. 16, comes after Pershing Square and Valeant last week decided to pay US$290 million to settle the lawsuit that accused them of insider trading before bidding for Allergan Plc (AGN.N) in 2014.

The lawsuit was filed on behalf of investors who sold Allergan shares in the two months before Pershing Square Capital Management and Valeant made an unsolicited US$51 billion bid for Allergan.

The court has "substantial questions regarding whether the settlement amount is reasonable and fair," according to documents filed in the U.S. District Court, Central District of California.

"Today's order is a mandated step in the settlement process," a Valeant spokeswoman said in an email to Reuters. "We believe the settlement is fair, reasonable and adequate, and we look forward to explaining our position to the Court."

Pershing Square could not be reached for comment outside regular business hours.