Advanced Micro Devices, which is struggling to reverse a string of quarterly losses, said Friday that senior VP and chief technology officer Phil Hester has resigned. Hester is the third senior executive to leave AMD in less than a year.

Hester's resignation was not related to a recent financial warning from AMD, a company spokesman said. AMD on Monday said it would reduce its workforce of 16,000 by about 10% and said revenue in the first quarter fell 15% from the fourth quarter of last year.

"He's pursuing other opportunities," the spokesman said of Hester. "He has not disclosed his future plans."

Hester, a 23-year IBM veteran who joined AMD in 2005, was in charge of the overall technical direction of AMD, as well as establishing the processes for recruiting, retaining, and promoting engineers, the spokesman said. On the technical side, Hester was in charge of bringing AMD's next-generation microprocessor, called Fusion, to market in the second half of next year.

Fusion, which AMD is calling an "accelerated processing unit," combines a graphics processor and a CPU on the same piece of silicon. The company is marketing the chips as a new class of x86 processing.

Mike Uhler, former CTO of chipmaker MIPS Technologies and VP of accelerated computing at AMD, will take full responsibility of Fusion and report directly to Dirk Meyer, president and chief operating officer of AMD, the spokesman said.

Hester, 52, will not be replaced, and his other responsibilities will be spread among the CTOs of AMD's five business units, Prairie said.

In less than a year, AMD has lost two other senior executives. Henri Richard, chief of sales and marketing, left in September, and David Orton, head of the graphics unit, left in July.

AMD in January reported that losses widened in the last quarter of 2007 to $1.77 billion, mostly because of charges related to the 2006 acquisition of graphics chipmaker ATI Technologies. The net losses were nearly triple the losses reported during the same period in 2006, and the fifth consecutive quarterly loss.

AMD has struggled to regain the market share it lost to Intel over the last year. AMD grabbed share from its larger rival between 2003 and 2006 following the release of its Opteron server processor that caught Intel off guard. Intel has come back, however, delivering on an aggressive product road map.

Nevertheless, AMD executives have said they are confident that the company would return to profitability in the second half of this year, driven primarily from new products, including the introduction of the company's first 45-nanometer microprocessors, also expected in the second half of this year.

The manufacturing process used in building the chips shrinks the size of the transistors to 45 nanometers, which means more transistors on each processor and therefore more power at the same level of energy consumption. Intel has been shipping 45-nanometer processors since the fourth quarter of last year.