By AppleInsider Staff

Published: 11:00 AM EST

Apple Computer this month has begun to slow production of its existing Core Duo MacBook Pro professional notebooks ahead of refreshed models that will sport Intel Corp's higher-performance Core 2 Duo microprocessors, AppleInsider has learned.

While Apple's online store continues to list immediate availability of Core Duo MacBook Pro models, the company this week is quoting some of its distribution and reseller partners wait times of 2 to 3 weeks for new custom-configured orders.

These reports are joined by tips from insiders who say the Cupertino, Calif.-based company is preparing to begin -- if it has not done so already -- manufacturing ramp of its holiday line of MacBook Pro notebooks.

The Mac maker last month was reported to have completed development of revisions to its entire notebook product family, including new 15- and 17-inch professional MacBook Pros as well as new 13-inch consumer MacBooks.

The new models are expected to sport similar specifications to existing models, but exchange their Core Duo microprocessors for Intel's new Core 2 Duo chips, which run at speeds of up to 2.33GHz dual-core.

It remains unclear whether Apple will refresh both notebook lines simultaneously, or if it will hold off the introduction of updated 13-inch MacBooks in order to reduce inventories of Core Duo processors.

Unlike the MacBook Pro, which began shipping in February, the MacBook remains a relatively new product by Apple's historical standards, having been introduced just four and a half months ago. The MacBook also remained in high-demand through September (outselling MacBook Pro by a more than 2 to 1 ratio) while demand for the MacBook Pro was more subdued.

Nevertheless, people familiar with Apple's plans say the company is on track to updated both notebook lines prior to the holiday shopping season, which kicks off in typical chaotic fashion the day after Thanksgiving.