Apple

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refreshed its lineup of high-end professional desktop computers on Thursday, addressing one of the few soft spots in its catalog.

The company also announced that it is slashing prices on its flat panel displays by as much as $500 each. The move is the latest in a series of price cuts by Apple on a wide variety of offerings.

As part of the computer lineup changes, Apple unveiled three new models of its Power Mac G5 computers, replacing all but the entry-level model in the line. The introductions mark the first time the company has upgraded the top models in its Power Mac line since last June.

In recent quarters, sales of Apple's other computer lines have risen significantly, while sales of its iPod music players have surged. But the Power Mac line has stumbled. Unit and dollar sales of the line declined both sequentially and on a year-over-year basis in the company's recently completed second quarter.

Like the models they are replacing, all three of the new Power Macs will have two PowerPC G5 processors at their core. The low-end model, with a base price of $1,999, will include two 2.0 GHz PowerPC processors. The $2,499 midrange model has two 2.3 GHz PowerPC chips. And the $2,999 top-end model has two 2.7 GHz PowerPC chips in it.

The previous lineup, which sold for the same prices, had chip speeds ranging from 1.8 GHz on the bottom end to 2.5 GHz on the top end.

The base configurations of all three of the new Power Macs include at least 512 MB of SDRAM. And the base configurations of the top two models now include a 260 GB hard drive. Previously, the base configurations of those models included a 160 GB hard drive.

All three models will include Mac OS X "Tiger," the recently released update to Apple's operating system.

Although Apple has never really gotten a foothold in the larger corporate world, it has been the dominant or leading player in particular niches, such as graphics design and video and audio production. The company targets its Power Mac computers at professionals in those creative industries.

Indeed, on its site, the company claims that its top-of-the-line Power Mac runs

Adobe's

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Photoshop program, a photo-editing program used by photography professionals, two times faster than a computer based on

Intel's

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Pentium 4 processors.

The company sells its Power Macs sans displays, which is where its Cinema Display flat-panel screens come in. The company is now offering its low-end 20-inch model for $799, a midrange 23-inch one for $1,499, and a top-of-the-line 30-inch model for $2,999. Previously, the company charged $1,299, $1,999 and $3,299, respectively, for the models.

Apple has a reputation for charging more than its competitors for like products, and critics have argued that such price practices have limited the company's market share. But the company has been increasingly price competitive in recent months.

Earlier this year, Apple

introduced the Mac Mini, a budget-priced Macintosh computer, and the iPod Shuffle, a low-end digital music player. The company has also slashed prices on its high-end

iPod photo and its

PowerBook line of notebook computers.

In recent trading, Apple's shares were off 7 cents, or less than 1%, to $36.12.