AUSTIN, Texas — Motorola Inc. and IBM Corp. said on Thursday that they will end their joint ownership of the Somerset PowerPC microprocessor design center in Austin, Texas, and leave Motorola as its sole proprietor.

The companies decided to part ways on Somerset after both realized that they need more resources to focus on designs for different embedded markets, a Motorola spokesman said.

Despite the split, the companies said they will "continue to cooperate closely on the PowerPC architecture and its advancement in the marketplace while expanding their respective design capabilities."

The companies will continue to work on an embedded microprocessor initiative, announced last fall, which calls for their participation in an Architectural Review Board. The board, which also includes Apple Computer Inc., oversees the long-term direction of the PowerPC architecture.

The only change between the two companies will involve "the amount of design resources under Motorola's control which will be focused on target markets most beneficial to Motorola," said a spokesman for Motorola's Networking and Computing Systems Group.

The spokesman declined to specify the financial commitment Motorola will make to take ownership of the center, but said he believed it would be included in the $1.95 billion write off Motorola announced last week to stem the effects of deteriorating demand and price pressure. Without being specific about the number of employees who will remain at the center, he said it employed "several hundred" when operated by both Motorola and IBM.

The changes at Somerset, which was established in 1992, comes a week after Motorola took strong steps to stem the effects of the Asian financial crisis. The company said it would cut 15,000 employees in an effort to trim costs.

Motorola and IBM said they will each pursue Apple Computer as a customer will still be able to second-source each other's parts "when it makes business sense," the Motorola spokesman said.

Both companies consider collaboration on the PowerPC architecture for embedded applications to be crucial, as both view the architecture as necessary for long-term survival.

Motorola will continue to add enhancements and extensions to its existing PowerPC microprocessors for use in Apple's desktops, but will also expand its offerings for the network switching and transmission infrastructure.

While "there is still demand for increasing performance at the desktop," those systems are no longer the sole driver of PowerPC.

Meanwhile, IBM said it will develop high-end PowerPC microprocessors for its server products and will continue to develop PowerPC embedded controllers.

Both companies affirmed the importance of the PowerPC to their respective strategies and product lines. Four of IBM's server lines are based on the PowerPC, the company said.

IBM's current employees at Somerset will be offered careers at Motorola. Motorola intends to increase staffing levels at Somerset in the future due to rising customer demand for PowerPC-based designs, the company said.

The center will henceforth be headed by Bertrand Cambou, senior vice president and general manager of Motorola's Networking and Computing Systems Group.