SAN FRANCISCO, US: Apple Inc on Monday said strong demand for its new iMac personal computer had it working hard to keep up, and the company apologized for any delays in deliveries to customers.

The new 27-inch iMac starts at $1,699. According to Apple's online store, the desktop PC ships in 2 weeks. By contrast, the 21.5-inch model ships in 24 hours.

"The new iMac has been a huge hit and we're working hard to fulfill orders as quickly as possible," said Apple spokesman Colin Smith "We apologize for any inconvenience or delay in delivery this may cause our customers."

He declined to comment on reports on Apple-focused websites about display problems on the 27-inch iMac. Sites such as AppleInsider have noted growing reports about "flickering screens and yellow-tinged displays."

Apple began selling the new iMac models in October. Industry analysts have reported strong consumer demand for the Mac lineup this fall. Apple is the No. 4 PC maker in the United States, according to IDC, but its products carry a much steeper premium than rival PCs.

In the September quarter, Apple sold 3.05 million Macs, up 17 percent from the year-ago quarter.

In October, Apple reported difficulty meeting demand for the iPhone last quarter.

Shares of Cupertino, California-based Apple closed at $196.98 on the Nasdaq, up 1.2 per cent.