By Slash Lane

Published: 10:00 AM EST

With sales of Macs maintaining growth rates of more than two times the industry average and a pair of hefty portable updates in the pipeline, Apple is reported to have increased sharply its procurement of notebook-use circuit boards for the third calendar quarter.

Citing its usual sources, Chinese-language Commercial Times said Friday the Mac maker has sought some 20 percent more high-interconnect density (HDI) notebook motherboards for manufacturing ramps that will take place sometime during the three month period ending September.

Apple is believed to finalizing development of overhauled MacBooks and MacBook Pros that should make their way to manufacturing during this period. The hardest evidence to this end surfaced earlier this month when the new exterior design of the latter notebook family was revealed in a photograph of a leaked prototype casing believed to have been taken outside the company's partner facilities in Taiwan.

With iPods finally believed to be reaching their saturation point, Macs have have assumed the role of Apple's second primary growth drive next to the iPhone. In a research report issued to clients Friday, Piper Jaffray analyst Gene Munster said NPD market research data from the first two months of the company's June quarter suggests Mac sales may be up 50 percent year-over-year.

Apple's fiscal third quarter earnings report due Monday should offer some additional color on the matter. For his part, Munster is modeling the company to announce sales of 2.35 million systems for the three month period ended June 30th, which would represent 33 percent yearly growth.

"Typically NPD over estimates actual Mac unit growth," he said. "If Apple sells 2.35 million units, it would be a significant positive."

Munster reiterated his Buy rating and $250 price target on the company, citing his own expectations of refreshed MacBook and MacBook Pros in the September quarter coupled with increased demand from the ongoing educational buying season.