The news division has been in turmoil in the aftermath of the "Dateline NBC"-General Motors scandal. In February, the network admitted that its "Dateline NBC" newsmagazine had rigged a crash test for a November segment on the safety of GM pickup trucks. The admission, coupled with NBC's apology, settled a defamation lawsuit filed by GM.
Mr. Gartner announced his resignation March 2.
Mr. Lack joined the CBS in November 1976 as a producer for a personality magazine called "Who's Who." He was named executive producer of "Street Stories" in January 1992. For 17 months before that, Mr. Lack was executive producer of news specials and documentaries.
Mr. Lack introduced the use of re-creations at CBS News in the late 1980s, and soon dropped them.
During his CBS tenure, Mr. Lack, 45, was the creator and executive producer of two prime-time newsmagazines: "Face to Face With Connie Chung" and the high-tech "West 57th." His broadcasts have won 16 Emmys and two Peabody Awards.