As a Senate committee prepared to compel his testimony about his role in Enron's ( ENRNQ) implosion, former Chairman and CEO Kenneth L. Lay said late Monday that he would resign immediately from the company's board of directors. The announcement came on the heels of his abrupt decision Sunday evening not to voluntarily testify before Congress as originally planned. Lay was scheduled to testify Monday and Tuesday before House and Senate committees that are investigating the reasons for Enron's demise. In response, Sen. Byron Dorgan (D., N.D.) said Monday that the Senate Committee on Commerce, Science and Transportation would issue a subpoena compelling Lay to testify. A House committee began similar action Monday afternoon. A report authored by a committee of Enron's board was released Saturday, and its findings were critical of Lay's role in Enron's implosion. The company filed for bankruptcy in December. Lay, 59, resigned his positions as chairman and chief executive Jan. 23 under pressure from the board for outside leadership.