A co-defendant accused of shipping cocaine under Manuel Noriega's protection entered plea negotiations with prosecutors Wednesday minutes after a judge allowed his jailhouse confessions into evidence.

But the plea by William Saldarriaga was not firm, said Richard Sharpstein, lawyer for Brian Davidow, another co-defendant of the ousted Panamanian dictator.The plea was expected to be decided before jurors were to hear lawyers' opening statements in the case Wednesday afternoon.

Saldarriaga, 44, and Davidow, 29, are accused of conspiring to ship 322 kilograms of cocaine aboard the boat Krill in March 1986.

After Saldarriaga's arrest, he allegedly admitted his involvement with the Krill to inmates at the federal Metropolitan Correctional Center and sent a letter to lead prosecutor Michael Sullivan offering to plead guilty.

Saldarriaga's attorney, Steven Kreisberg, challenged the confessions, saying inmates were illegally acting as government agents to pressure his client into a plea bargain.

But U.S. District Judge William Hoeveler ruled Wednesday that "there is no indication of any surreptitious placement of anyone with him or around him."