SEOUL (Reuters) -Nvidia supplier SK Hynix on Thursday boosted its 2025 investment plan after posting a record quarterly profit as it seeks to alleviate investor concerns about slowing growth for artificial intelligence chipsets.

The South Korean chipmaker expected a "low likelihood of sharp decline in demand" in the second half, citing a stable customer inventory level and demand growth driven by new model launches by customers.

SK Hynix said it was on track to double high-bandwidth memory (HBM) chip sales for the full year compared to 2024.

The company's revision of its capital expenditure to proactively respond to customer demand for next year, "appears to reflect its confidence" as it faces major competition from Samsung Electronics next year, said Ryu Young-ho, a senior analyst at NH Investment & Securities.

In March, SK Hynix said it planned to finalise sales with customers for the 2026 volume within the first half of this year.

"SK Hynix foresees that increasing competition among big tech companies to enhance inference of AI models would lead to higher demand for high-performance and high-capacity memory products," it said in a statement.

SK Hynix reported a 9.2 trillion won ($6.69 billion) operating profit for the April-June period, up 69% from 5.5 trillion won a year earlier.

That compared with a 9.0 trillion won average forecast by LSEG SmartEstimate, which is weighted toward analysts who are more consistently accurate. Revenue rose 35% to 22.2 trillion won during the quarter.

Its profit is double the quarterly operating profit expected by crosstown rival Samsung Electronics , which this month projected a worse-than-expected 56% plunge in second-quarter operating profit due to weak AI chip sales.

SK Hynix overtook Samsung Electronics as the world's top memory chip maker in the first quarter due to its leadership in HBM chips, a crucial component of AI chipsets designed by the likes of Nvidia that assist the processing of vast amounts of data to train AI models.

After posting a series of record profits boosted by strong AI demand, SK Hynix is bracing for potential U.S. tariffs and rising competition from rivals in supplying advanced chips to Nvidia, analysts say.

Earlier this month, U.S. President Donald Trump threatened to soon introduce tariffs on semiconductors. SK Hynix said in April that the proportion of its exports to the United States was not high, but analysts said the company could face pricing pressure from customers squeezed by U.S. tariffs.

Last Thursday, SK Hynix saw its shares close about 9% lower after Goldman Sachs downgraded the stock to "neutral," expecting HBM prices would decline for the first time next year.

Shares of SK Hynix are up 54.7% so far this year, outperforming the KOSPI's 32.7% rise.

($1 = 1,374.5800 won)

(Reporting by Heekyong Yang and Joyce Lee and Hyunjoo Jin; Editing by Leslie Adler, Jamie Freed and Lincoln Feast.)