Apple's forthcoming new iMac will be based on a G5 processor, the company revealed last night.

Speaking to analysts, chief financial officer Peter Oppenheimer confirmed the new iMac - scheduled to ship in September - will be based on a G5. He added that the delay in shipping the new Mac has been cause by supply problems of the processor, which is manufactured by IBM in New York.

iMac picture

"We normally don't talk about unannounced products but we feel you need to know about the current situation. The new iMac will be based on a G5 processor. We could not secure the necessary supply of G5 processors to launch the new iMac on schedule. We now plan to announce and ship it in September."

He described Apple as "extremely unhappy" at these events.

"IBM's supply issues are the industry's supply issues", he said, adding that the move to new 90-nanometre chip manufacture has not been as smooth as expected. "IBM has made progress in sorting out those issues," he said.

"This resulted in a mass loss of our wafer supply and lower than anticipated yields", he said.

"IBM has placed enormous resources on solving this problem, and based upon what they have told us we expect these problems to be behind us by fiscal Q1 2005," he promised.

He added: "Our Power Mac G5 shipments were constrained in the quarter by a manufacturing problem at IBM that caused significant delay in shipping those processors."

These problems will "impact on the September quarter as well," he said, warning of anticipated shortages in dual 1.8-GHz and dual 2.0GHz Power Mac G5s, but promising that this would improve in August.

"We expect to have shortages of our high-end dual 2.5GHz Power Mac G5s throughout the next quarter", he said.