SEOUL, March 25 (Reuters) - South Korean chipmaker SK Hynix announced on Wednesday it made a confidential filing for a U.S. listing in 2026, which a source said could raise as much as $14 billion.

SK Hynix plans to list about 2% to 3% of its total shares and hopes to use the funds to help finance its work in chip factories in South Korea's Yongin city and the U.S. state of Indiana, a person with direct knowledge of the discussions told Reuters.

The company, one of the world's largest makers of memory chips, has been expanding production capacity to keep up with strong demand for artificial intelligence data centers. SK Hynix's shares were trading 3.8% higher on Wednesday morning.

Confidential filings allow companies to withhold details about their finances and offering terms until closer to the actual listing.

A 2% to 3% share issue would equate to $9.6 billion-$14.4 billion of SK Hynix's market capitalisation, and potentially more than double Coupang's $4.6 billion U.S. IPO in 2021, according to Reuters' calculations based on its Tuesday closing share price.

SK Hynix did not immediately respond to a request for comment on the fundraising size.

The company, in a domestic regulatory filing on Wednesday, said: "While we aim to complete the listing within 2026, specific details - such as the size, structure, and timeline of the offering - have not yet been finalized."

The Korea Economic Daily reported earlier this week that SK Hynix was considering raising 10 trillion to 15 trillion won ($10.03 billion) by issuing new shares in a U.S. listing.

CLAMOUR FOR SHARE BUYBACK

The Korea Corporate Governance Forum, an advocacy group that comprises investors and lawyers, said on Wednesday it opposes SK Hynix's potential issuance of new shares for the U.S. listing, saying the move would dilute the value of existing shares, and undermine Korea's revised legislation to protect the interests of all shareholders.

The forum said SK Hynix will be able to generate more than enough excess cash flow even after making capital expenditure and R&D investments during 2026-28, and urged the company to buy back 10% to 15% of its stock and use most of that for the U.S. listing.

SK Group Chairman Chey Tae-won said last week SK Hynix is reviewing a potential U.S. ADR listing to increase exposure to global investors.

"The decision was disappointing," said Kim Hyun-su, a fund manager at Seoul-based IBK Asset Management. "I don't understand why they have to issue new shares - they can probably pursue the listing using existing shares instead. If they conduct buybacks and then seek the U.S. listing, it would make everyone happy." 

Reuters reported in January that the firm plans to accelerate the opening of a new plant in Yongin city to February 2027 to meet rising demand for memory chips.

SK Hynix said on Tuesday it will purchase 11.95 trillion won worth of ASML's EUV lithography tools, used to create chip circuitry, in the largest single order publicly disclosed by an ASML customer.

The company has been the top supplier for high bandwidth memory (HBM) semiconductors used in artificial intelligence chipsets designed by the likes of Nvidia, but cross-town rival Samsung Electronics has been trying to narrow the gap with the latest HBM4 chips.

(Reporting by Cynthia Kim, Hyunjoo Jin, Jack Kim and Heejin Kim; Editing by Chris Reese, Christopher Cushing and Muralikumar Anantharaman)