*

Plane carrying Korean workers arrives in Incheon

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New visa category for South Koreans under discussion after

raid

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South Korean President has warned firms may be hesitant to

invest in US

(Writes through after plane's arrival in South Korea)

By Joyce Lee and Jihoon Lee

INCHEON, South Korea, Sept 12 (Reuters) - Some 300 South

Korean workers returned home on Friday, one week after being

detained in a large-scale U.S. immigration raid at a battery

project site in Georgia.

Workers wearing face masks began disembarking a chartered

plane at Incheon airport and were greeted with cheers from

officials including the presidential chief of staff.

Their return capped a week of intense negotiations by Seoul

to win their release and bring them home after they were taken

into custody in handcuffs and shackles - shocking many in South

Korea, a key U.S. ally.

South Korean businesses have long struggled with obtaining

proper visas for specialist workers needed at project sites for

months at a time, which has led to some workers relying on grey

areas in U.S. visa enforcement.

The two countries are looking at establishing a working

group to consider a new type of visa for Koreans, according to

South Korea's foreign minister who visited Washington this week.

The workers, also including 10 from China, three from

Japan and an Indonesian national, were met by family members and

officials at LG Energy Solution, and its

subcontractors. The battery company is partnering with Hyundai

Motor ( HYMLF ) to build the plant in Georgia.

The raid horrified South Koreans and has threatened to

destabilise ties at a time when the countries are seeking to

finalise a trade deal, which includes a $350 billion investment

fund to support strategic U.S. industries.

In one sign of resentment, at the arrival gate, someone

unfurled a poster depicting U.S. President Donald Trump wearing

an outfit with the initials of the U.S. Immigration and Customs

Enforcement service and carrying a bag full of dollar bills with

a machine gun slung across his chest. The caption read: "We're

friends!".

South Korean Foreign Minister Cho Hyun, who flew to

Washington this week to seek a quick resolution, has called on

U.S. officials to come up with a new visa for workers at Korean

businesses investing in the United States.

President Lee Jae Myung warned on Thursday that the incident

could make South Korean companies hesitant about investing in

the U.S at a time when Trump has been seeking to encourage

foreign investment in manufacturing.

(Reporting by Joyce Lee and Jihoon Lee; Additional reporting by

Ju-min Park and Hyunjoo Jin; Editing by Ed Davies and Edwiina

Gibbs)