CUPERTINO, CALIF. -- Apple Computer Inc., powered by a $40 million advertising blitz, will launch a new line of three smaller, less-expensive products today aimed at boosting sales.

"I think we realize it's a war out there," Product Director Brodie Keast said, acknowledging that the major shift in strategy from expensive home computers to smaller, high-capacity units costing as little $999 is aimed at bolstering the company's slipping share of market sales.

Apple will pin its hopes on:

The $999 Mac Classic for first-time buyers. The Classic comes with a black-and-white, 9-inch screen, one floppy-disk drive and 1 megabyte of memory. It uses the Motorola 68000 microprocessor of the original Mac but can be easily upgraded with snap-on parts for more memory and a hard-disk drive. The upgraded price is $1,499. The Classic is expected to replace the Mac Plus and SE.

The $3,098 Mac LC with low-cost color monitor. Until now, color Macs started at $6,316. The Mac LC uses the 68020 chip and has 2 megabytes of memory, a hard-disk drive and one expansion slot. The Mac LC is expected to compete in the business computer arena against IBM's best-selling PS/2 Model 55SX, which ranges in cost from $4,000 to $7,000.

The $3,769 Mac IIsi, a low-priced, high-powered computer that uses the 68030 chip. The IIsi comes with 2 megabytes of memory, but can be upgraded to 17, and 80 megabytes of disk-drive capacity. The computer is aimed at replacing the much more expensive SE 30 model.

At stake, when Apple unveils the new computers during a special ceremony today at its manufacturing plant in Fremont, Calif., is the company's share of the $42.3 billion U.S. personal computer market.