TAIPEI -(Dow Jones)- Hon Hai Precision Industry Co. (2317.TW), the world's largest contract electronics maker by revenue, said Saturday it plans a total of US$106.15 million investments in its Chinese units, including robotic machinery to increase automation as rising labor costs weighed on its profitability.

The main supplier of Apple Inc's (AAPL) iPad and iPhone said it will invest in several Chinese operations including robotic machinery, printed circuit board, handset testing and packaging and microprocessor manufacturing.

The investment plans comes as Hon Hai reported a first-quarter net profit increase of 3.6% from a year earlier as a wage hike bit into earnings.

Hon Hai, which assembles products for companies including Apple Inc. and Sony Corp. (6758.TO, SNE), said its net profit for the three months ended March 31 rose to NT$14.92 billion from NT$14.40 billion a year earlier.

Its net profit was below the average NT$22.10 billion forecast of eight analysts polled by Dow Jones Newswires, mainly because its operating expenses rose 12% to NT$758.18 billion from NT$676.42 billion a year earlier following a February wage hike for assembly line workers in China.

-By Lorraine Luk, Dow Jones Newswires; 8862-25022557; lorraine.luk@dowjones.com