Broadcom has warned of a broad slowdown in chip demand, blaming a trade conflict between the US and China and export restrictions on Huawei Technologies.

The US chipmaker cut its revenue forecast for the year by 8%. 

Shares of the California-based company fell 8% in extended trading and the remarks dragged down stocks of other chipmakers, including Qualcomm, Texas Instruments and Skyworks Solutions. 

"It is clear that the US-China trade conflict including the Huawei export ban is creating economic and political uncertainty and reducing visibility," chief executive Hock Tan said. 

Shares of Broadcom have been under pressure after the US government put Huawei on a trade blacklist last month. Huawei accounted for about $900m, or 4%, of the company's overall sales last year. 

Tan said that if consumer demand for smartphones remains steady, other phone makers could start taking Huawei's market share, and those phone makers are likely to buy chips from Broadcom. 

However, he cautioned that the process will take up to six months. 

"What's the impact of the Huawei ban on a company like us selling components and technology? Well, short term, keep in mind we'll see a very sharp impact simply because (there are) no purchases allowed and there's no obvious substitution in place," Tan said. 

Revenue from semiconductor solutions, Broadcom's biggest business unit, fell 10% to $4.09 billion in the second quarter, while revenue from its infrastructure software business came in at $1.41 billion. 

Demand for enterprise and mainframe software remained stable, mainly in North America and Europe, Tan said. 

The company, known for communications chips that power Wi-Fi, Bluetooth and GPS connectivity in smartphones, lowered its full-year revenue forecast by $2 billion to $22.50 billion, saying that its customers are actively reducing inventory levels. 

Net revenue rose to $5.52 billion in the quarter ended May 5, from $5.01 billion a year earlier, but missed analysts' estimates of $5.68 billion, according to IBES data from Refinitiv. 

Net income fell to $691m, or $1.64 per share, in the quarter, from $3.72 billion, or $8.33 per share, a year earlier.

Excluding items, the company earned $5.21 per share, beating analysts' estimates of $5.16 per share.