Four area businesses were recently fined by the regional office of the Immigration and Naturalization Service for hiring illegal immigrants from a popular day-labor pickup site in Silver Spring, officials announced this week.

The site, a 7-Eleven convenience store parking lot at Piney Branch Road and University Boulevard, has been raided by immigration agents three times since August -- most recently on Nov. 8 -- in an effort to control what they say is the state's largest "hiring hall" for illegal immigrants.

Undocumented workers gather each day in the parking lot for an opportunity to get temporary jobs with contractors, painters and people who drive by and hire on the spot.

The raids have caused an uproar among community activists in Silver Spring and nearby Takoma Park, many of whom are asking the Takoma Park City Council to set up a city-sanctioned hiring hall that might discourage intervention by the immigration service.

Louis F. Nardi, assistant district director for investigations at the agency, said that at least four more businesses remain under investigation for violating the employer sanction provision of the Immigration Reform and Control Act of 1986.

Two of the companies under investigation are being referred to the U.S. Department of Labor for possible violation of the fair wage and hour labor laws, Nardi said.

The sanctions taken this week against three construction companies and a bowling alley come at a time when civil rights groups, particularly Hispanic ones, are calling for a repeal of the employer sanction provision of the law.

The provision makes it illegal for employers to hire illegal immigrants, or to fail to properly check an employee's identity or work authorization status.

Hispanic activists have said this provision causes discrimination against foreign-looking or foreign-sounding job applicants.

A recent General Accounting Office report concluded that the employer sanction rule has created a pattern of discrimination by employers who are afraid of breaking the law.

The four companies punished were Tito Contractors, of Washington, fined $12,500; Iberica Construction Co., of Hyattsville, fined $4,300; USA Number 1 Contractors, of Silver Spring, fined $3,700; and Golden Cup Billiards, of Odenton, fined $2,500.

Iberica and Tito Contractors have been fined previously for similar violations, Nardi said.

None of the companies could be reached for comment yesterday.