Apple Inc. (AAPL) and Samsung Electronics Co. (005930) face a $3.9 billion challenge as they prepare to sell new marquee phones in the world’s biggest wireless market. China’s state-run wireless operators are slashing subsidies they pay to make devices more affordable for consumers just as the biggest phone-makers are set to introduce upgraded products. After China Mobile Ltd. (941) said it will cut subsidies by $2 billion, its competitors will lower payments by $1.9 billion, according to analysts’ estimates. China Telecom Corp. said yesterday it will cut spending without giving a figure.