BOSTON (Reuters) - Can Macworld exist without the help of big Apple?

That was the question on Macintosh users' minds on Thursday after a bitter Apple Computer Corp. AAPL.O said it would not participate in the huge trade show when it comes to Boston in 2004.

Macworld organizer IDG World Expo announced earlier in the day what had been rumored for weeks: that it had struck a deal with Boston authorities to bring the trade show back to Massachusetts in July 2004.

But within two hours of IDG's announcement, Apple said in a terse statement that it was not pleased with the move.

"Apple disagrees with this decision, and will not be participating in Macworld Boston," Apple said, declining to comment on the reason for its disagreement.

The Cupertino, California-based computer company also said it would rethink its participation in next year's New York Macworld.

"Since IDG is no longer investing in New York, we now need to re-evaluate our participation in Macworld New York 2003. Apple will continue to participate in Macworld San Francisco in January," Apple said.

IDG said it had kept Apple informed of the plan to move Macworld to Boston and that it could "only speculate" about the company's objections.

Macworld takes place twice a year, with one show in San Francisco. The shows typically feature an appearance by Apple founder and Chief Executive Steve Jobs, who enthralls Mac users with a display of the latest products.

Macworld left Boston for New York in 1998 after outgrowing the city's available convention space. IDG said the trade show's return to Massachusetts was expected to bring at least $40 million to Boston.