Tenneco Inc. President Michael H. Walsh will...

Tenneco Inc. President Michael H. Walsh will assume duties as chief executive effective Jan. 1, the Houston-based company said.

Walsh, 49, was elected chief executive at the company’s regular board meeting Dec. 9. He will succeed James L. Ketelsen, who remains chairman. The board also said it intended to name Walsh chairman at the company’s May 12, 1992, annual meeting, when Ketelsen retires.

Walsh came to Tenneco in August after serving as chairman and chief executive of the Union Pacific Railroad Co. since 1986. Tenneco said then that Walsh would be in line to take over the top duties.

Since joining Tenneco, the company has begun a $2-billion restructuring, which has included sales of $686 million in assets and layoffs of 4,000 employees by the end of 1992 from its JI Case farm and equipment unit.