* SK Hynix ( SKHY ) board approves 54.3 trln won investments for

Yongin, Cheongju chip plants

* Yongin HBM/DRAM, Cheongju NAND fabs to begin construction

in 2027

* Actively reviewing additional shareholder return measures;

details due in third quarter

(Adds details of the investment, SK Hynix ( SKHY ) statement from

paragraph 3)

SEOUL, Aug 7 (Reuters) - South Korea's SK Hynix ( SKHY )

said on Friday that its board had approved about 54.3 trillion

won ($38.30 billion) of investments through 2031, including 35.2

trillion won for the second phase of construction of its chip

fabrication plant in Yongin and 19.1 trillion won for its M17

chip plant in Cheongju.

In June, SK Hynix ( SKHY ) said it planned to invest 600 trillion won

in the Yongin semiconductor cluster and 100 trillion won to

expand its production base in Cheongju, adding at the time that

detailed investment plans and schedules would be disclosed after

receiving board approval.

The company said Yongin's "Y2 fab" is the second of four

fabrication plants planned for the cluster and will serve as a

production base for dynamic random access memory (DRAM) chips.

DRAM, which temporarily stores data ​for processors, is a

critical component in the servers ⁠powering the AI boom.

Construction is scheduled to begin in July next year, with

the first cleanroom expected to open in June 2029 to produce

high-bandwidth memory (HBM) and other next-generation DRAM

products. A cleanroom is a highly controlled manufacturing space

that keeps dust and other microscopic contaminants out during

the chipmaking process.

Meanwhile, the first-phase Yongin fab remains on track, with

its first cleanroom scheduled to open in February next year, the

company said in a statement.

Separately, SK Hynix ( SKHY ) said construction of the M17 fab in

Cheongju, which will produce NAND flash memory used to store

data in devices ranging from personal computers to AI servers,

is scheduled to begin in February next year, with its first

cleanroom expected to open in December 2028.

In a separate regulatory filing, the company said it was

"actively reviewing" additional shareholder return measures to

enhance shareholder value and expects to finalise and announce

details in the third quarter.

($1 = 1,417.8300 won)