The Justice Department said yesterday it would not challenge Tenneco Inc.'s proposed acquisition of a portion of International Harvester, and Tenneco officials said they would complete the transaction today.

Tenneco announced Nov. 26 that it would spend $430 million to acquire selected assets of Harvester's unprofitable farm equipment operation. The Justice Department's antitrust division initiated a 60-day review of the proposal, and closed the books on that investigation yesterday, a department spokeswoman said.

"We are pleased with the decision of the Justice Department," said Tenneco Chairman James Ketelsen. "We can now continue the process of fitting together the two operations to build a profitable farm and construction equipment organization that is second to none in sales, service and support."

Harvester Chairman Donald Lennox echoed Ketelsen's statement, and said in Chicago that the transaction should ensure a better financial future for his company.

"Although we are now a much smaller company, International Harvester has a more certain future as a leading manufacturer of medium and heavy-duty trucks and diesel engines," he said.

"With the closing of this transaction, International Harvester anticipates a return to profitability."

The farm implement firm of J. I. Case is a division of Tenneco, and the company believes a merger of Case and Harvester will provide a strong competitor for John Deere & Co., the industry leader.