FOREIGN brokers have slammed warnings against Baring Brothers and Jardine Fleming for alleged violations of securities laws as further evidence of Seoul's unease at lifting the ceiling on foreign investment in the stock market. Securities Supervisory Board (SSB) investigative division chief Shin Hae-ryong confirmed yesterday that the first audit since the firms began dealing in Seoul last year had found them both to be involved in minor infractions of security regulations. The foreign brokers, interpreting the action as the result of the financial authorities' lingering concern about the possible harmful effects of foreign investment in the stock market, take exception to ''insignificant'' procedural breaches being made public when Seoul is thought to be close to expanding the ceiling on foreign capital from 10 per cent to 15 per cent. ''Local brokers flout the laws left, right and centre,'' said one American broker. Jardine Fleming branch manager Philip Smiley said the caution involved ''technical, procedural matters which have already been corrected''. He said most of the irregularities referred to by the SSB had taken place nearly two years ago when the share market was first opened to foreign investors and regulators and brokers were unfamiliar with regulations. The audit was carried out in July and no follow-up action was expected. Jardine Fleming was cited for allegedly misusing securities cards and not informing clients of their balances, a charge Mr Smiley said referred to the firm's initial failure to send balance statements by registered mail. Mr Shin said Baring Securities had been found to have conducted irregular business such as opening deposits for foreigners who did not register their investments. Barings branch manager William Daniel said technical problems in making transactions by computer a month before the market was opened in January last year had been to blame. Both companies said steps had been taken to amend their market procedures. Some foreign analysts say such warnings still show the Seoul market is over-regulated. ''In any other market, with the possible exception of Taipei, no one would have bothered,'' said one foreign analyst. Several foreign brokerages claim Ministry of Finance officials have interfered with their attempts to attract Korean clients. ''Several potential Korean customers have been warned of tax investigations if they do business with us,'' said one foreign broker. Another foreign broker said the leak of the audit findings to the press in Seoul and recent government statements denying that foreign share limits would be increased might be efforts to ''talk down'' the market after its gain of more than 13 per cent inlittle more than a month.