Micron Technologies will not be opening its memory chip testing operation here this summer after all.

The Boise-based computer chip-maker announced Thursday that it is laying off all of its contract employees. It also said some regular workers are taking positions at the company's headquarters at the end of the month rather than wait indefinitely for the Lehi plant to open completely.One company representative said she did not have the number of contract employees that are out of jobs, but she did say the plant will open one day.

"No company puts more than $600 million into a plant never to open it," said Stan Lockhart, another company spokesman who works with Micron's Corporate Affairs Department in Lehi.

Lockhart said Micron has come up with a way to test memory chips in greater quantity at its Boise plant, making it unnecessary to open the Lehi facility. Also, Lockhart said, the price of DRAM memory chips has plummeted.

Julie Nash, Micron's corporate spokeswoman, said the downturn is lasting longer than anyone anticipated.

Downturns "usually go for 12 to 18 months, but this has been going on for two and a half years," Nash said. "We anticipate that, eventually, the cycle will change."

Lockhart said the company will retain about 200 employees at the Lehi facility.

Utah County Commissioner Gary R. Herbert said, "The disappointing thing is that the thing we waited for has not happened. The bright side is that it is not if, but when, it will open."

Micron officials told him last month that the plant could open within the next six months, Herbert said.

But Nash said the test facility will only open if the Boise plant gets backlogged again. As for when the entire facility will open, she said it depends on when the market improves.

Micron began construction on its facility in the summer of 1995, but it announced in February 1996 that it would have to mothball the plant because of the drop in prices for computer chips.

In an unrelated measure to cut costs, Micron Electronics Inc. announced Thursday it would lay off about 130 employees - 5 percent of its work force.

The company sold 6 percent fewer personal computers than last year, and in February it shifted about 450 employees to its parent company, Boise-based Micron Technology Inc., to begin reducing operating expenses.