Musa's Zhang Ziyi also starred in Crouching Tiger, Hidden Dragon

Seoul is keen for the BIT to attract more US investment for the economy.

In a statement, the actors and directors said the decision on which films were shown in South Korea's cinemas "should not be judged only by market principles".

They added that the screen quota system maintained Korea's cultural identity and diversity.

At a press conference to publicise their concerns, about 50 of the filmmakers chanted: "Stop conspiring to end or change the screen quota."

The big-name celebrities all wore purple and yellow bands reading: "Keep the screen quota as it is.

'Criticism'

"Stop the humiliating talks on signing the BIT with the United States. Oppose the BIT."

They added that repealing the quota would be a "suicidal act".

The statement followed local reports that US deputy trade representative Jon Huntsman, in South Korea last week, had criticised the quota.

Mr Huntsman was said to have warned that the US might not resume talks on the BIT.

Choi Hyuck, deputy minister for trade at the foreign ministry, was last week quoted by one newspaper as saying it was "time to reconsider the law" regulating the protective quota.

Record year

South Korea's cinema has been enjoying an unprecedented boom domestically and on the international stage.

Its films took a record 49.5% share of the local market last year.

Exports more than doubled, and record amounts of money were poured into the industry.

Musa (The Warrior), made in 2001, broke all records in terms of cost, production and challenges of shooting.

The number of foreign films screened fell to 355 last year, from 427 in 2000, according to data from the state-run film watchdog, the Korea Media Rating Board.