By Sruthi Shankar and Noel Randewich

(Reuters) - Nvidia dethroned Apple as the world's most valuable company on Friday following a record-setting rally in the stock, powered by insatiable demand for its specialized artificial intelligence chips.

Nvidia's stock market value briefly touched $3.53 trillion, slightly above Apple's $3.52 trillion, LSEG data showed.

Nvidia was last up 2.2%, with a market value of $3.52 trillion, while Apple's shares rose 0.9%, valuing the iPhone maker at $3.54 trillion.

In June, Nvidia briefly became the world's most valuable company before it was overtaken by Microsoft and Apple. The tech trio's market capitalizations have been neck-and-neck for several months.

Microsoft's market value stood at $3.20 trillion, with its stock up 1.3%.

The Silicon Valley chipmaker is the dominant supplier of processors used in AI computing, and the company has become the biggest winner in a race between Microsoft, Alphabet , Meta Platforms and other heavyweights to dominate the emerging technology.

Known since the 1990s as a designer of processors for videogames, Nvidia's stock has risen about 18% so far in October, with a string of gains coming after OpenAI, the company behind ChatGPT, announced a funding round of $6.6 billion.

Nvidia and other semiconductor stocks got a lift on Friday after data storage maker Western Digital reported quarterly profit that beat analysts' estimates, buoying optimism about data center demand.

"More companies are now embracing artificial intelligence in their everyday tasks and demand remains strong for Nvidia chips," said Russ Mould, investment director at AJ Bell.

"It is certainly in a sweet spot and so long as we avoid a big economic downturn in the United States, there is a feeling that companies will continue to invest heavily in AI capabilities, creating a healthy tailwind for Nvidia."

Nvidia's shares hit a record high on Tuesday, building on a rally from last week when TSMC, the world's largest contract chipmaker, posted a forecast-beating 54% jump in quarterly profit driven by soaring demand for chips used in AI.

Meanwhile, Apple is struggling with tepid demand for its smartphones. iPhone sales in China slipped 0.3% in the third quarter, while sales of phones made by rival Huawei surged 42%.

With Apple set to report its quarterly results on Thursday, analysts on average see its revenue climbing 5.55% year over year to $94.5 billion, LSEG data showed.

That compares with analysts' projections for Nvidia of nearly 82% revenue growth to $32.9 billion.