UPDATE 1-UMC leader Hu resigns; CEO, chairman jobs split

(Adds details on the executives, background)

SAN FRANCISCO, July 16 (Reuters) - Jackson Hu, chairman and chief executive of United Microelectronics Corp (2303.TW) (UMC.N), resigned from active leadership of the world's second-largest contract chipmaker on Wednesday.

Hu will become a senior adviser to the Taiwan company, which appointed Senior Vice President Stan Hung to succeed Hu as chairman. Chief Operating Officer Sun Shih-Wei will become CEO, UMC said.

The changes, announced after a board meeting on Wednesday, come as UMC and its larger rival TSMC (2330.TW) (TSM.N) face slowing sales growth as their customers work off rising inventories amid the global economic downturn.

TSMC and UMC are the world's top contract chipmakers, supplying companies such as Texas Instruments Inc (TXN.N), Qualcomm Inc (QCOM.O) and Nvidia Corp (NVDA.O).

Earlier this month, UMC reported a 7.3 percent year-on-year decline in June sales, its sharpest fall since March 2007.

"My top priority as CEO will be to ensure that we deliver solutions that target our customers' success as they face these times of economic uncertainty," Sun said in the statement.

Taiwan newspapers said the move was part of UMC's bid to improve corporate governance by separating the chairman and CEO roles.

"I feel that I have accomplished many of my objectives and that the timing is right for a younger and more energetic management team to take over," Hu said in the statement.