Analyst Gene Munster of NPD Group has said that he expects Apple to refresh the MacBook Air line-up in March.

His comments come after similar claims were made by Taiwanese trade press outlet Digitimes earlier this week.

However, both claims have been notable for a lack of supporting evidence - Munster's claims, reported by Apple Insider, talks merely of "a possible MacBook Air refresh in March".

Munster, though, said that NPD's data showed that growth in Mac sales in the current quarter appeared to be fairly flat, but that a refresh of the MacBook Air line-up could help boost sales, seeing the company reach 4.5 million units for the period.

For the quarter, Munster projects that Mac sales will make up 17 percent of Apple's revenue. He said that iPhone sales would reach between 32 and 34 million, down on the last quarter when Apple shifter 37 million units.