(Adds share price, compares with analysts' estimates)
Jan 24 (Reuters) - Western Digital Corp reported a bigger-than-expected 20.7 percent fall in quarterly revenue on Thursday, exacerbating concerns that a China-led slowdown in smartphone demand is weighing on sales of its data storage devices.
The company's shares fell about 5 percent after the bell. They closed up 6.7 percent at $40.14 in regular trading, lifted by a rally in chipmakers following better-than-expected results from Texas Instruments Inc, Xilinx Inc and Lam Research Corp, with the broader Philadelphia index ending 5.73 percent higher.
Investors have been keenly watching Western Digital's results for a better understanding into whether demand for DRAM and NAND chips - used in mobile devices, memory cards, USB flash drives and solid-state drives - had finally peaked after Micron Technology Inc in December indicated to a glut in the market.
And in January, top smartphone makers Apple Inc and Samsung Electronics Co Ltd issued warnings on sales.
The company's loss narrowed to $487 million, or $1.68 per share, in the second quarter ended Dec. 28, from $823 million, or $2.78 per share, a year earlier. 1/8https://reut.rs/2FKU1MV 3/8
Revenue fell to $4.23 billion from $5.34 billion.
Excluding items, the company earned $1.45 per share.
Analysts on average had expected a profit of $1.51 per share and revenue of $4.26 billion, according to IBES data from Refinitiv. (Reporting by Sayanti Chakraborty in Bengaluru; Editing by Sriraj Kalluvila)