SAN JUAN, Puerto Rico (AP) _ PaineWebber Inc. of Puerto Rico, the U.S. commonwealth's largest brokerage firm, refused to comment Thursday about a complaint it committed 1,600 violations of local securities laws.

The complaint, filed Wednesday by the island's Financial Institutions Commissioner, said three former brokers committed the violations in managing 18 clients' accounts in 1994, including making unnecessary trades to increase their commissions, San Juan newspapers reported.

The complaint also said local PaineWebber President Miguel A. Ferrer and former branch manager Milton Cofresi Facundo were negligent in not maintaining appropriate controls over the three brokers, Marcos A. Comas III, Eugenio Santoni and Stanley Zych Jr.

The three resigned from the firm in 1994 and no longer work in the securities industry, firm spokesman Augusto Font said.

A decision against the firm could result in the suspension or revocation of its operating license or the licenses of those cited, and fines of up to $8 million, the reports said.

The complaint, the result of an 18-month investigation, will be decided by an administrative judicial process.

Ferrer's secretary referred questions on the complaint to Font. Font said the firm would issue a response Friday.

Stock brokers and others in the industry said PaineWebber's aggressive sales tactics finally caught up to the firm, The San Juan Star reported.

The local securities law is modeled on U.S. law.

PaineWebber, the local subsidiary of the New York-based brokerage firm, has about twice the annual revenues of its closest competitors on the island, Smith Barney Shearson and Merrill Lynch.

The firm planned to host a special investment seminar, featuring experts from the U.S. mainland, at a luxury San Juan hotel Thursday evening.