Owners of 15 Cambridge liquor stores targeted in a recent sting operation plead guilty to selling alcohol to a minor in a hearing before the License Commission last night.

No penalties were handed down at the meeting yesterday. License Commission Chair Alex P. Rodriguez said the cases will be decided on the January 28 meeting of the commission.

But Rodriguez said Friday the stores will likely receive a suspension of their alcohol license for as little as one day or as long as a week.

Shops such as Broadway Market, Lil' Peach, Cardullo's and Louie's Superette--which are popular with Harvard students--were on the list of stores targeted in the city's sting.

Last night, the owners of these and the other stores listened as Cambridge police officer Michael T. McMahon, who organized the sting, described each of the employees who sold alcohol to the underage undercover constables. All but two owners agreed they recognized themselves or an employee.

Walter Sousa, manager of Prospect Liquor on Cambridge Street, shook his head as he listened to McMahon describe one sting in which two employees stood at the counter discussing the Boston Globe's article on the upcoming sting operation while selling asix-pack to a constable without asking him foridentification.

"It sounds like I served you guys myself," hesaid.

Frank Cardullo, owner of Cardullo's, listenedcalmly to McMahon's description of the woman whosold to each of the three constables.

"That's my mother," he said, "I'm not going tofire her."

Cardullo, who operates a gourmet food store,said he was embarrassed by the sting operation."Minors don't think of coming in here. We don'tsell six packs, only bottles--no cans. Our pricesare more expensive," Cardullo said.

Although upset, Cardullo said he believed itprovided necessary awareness of the problems ofalcohol sale to minors. "We certainly are moreaware of this thing than we've ever been,"Cardullo said.

Owner of the University Wine Shop, Paul DeRuzzo, said he hoped the operation was planned toraise shopkeepers' awareness rather than to punishspecific stores.

"I hope what they're trying to do is createpublic awareness," De Ruzzo said.

De Ruzzo said he believed the sting operation,whatever the motivation behind it, had done somegood. "I think it's keeping retailers on theirtoes. [These measures] might not keep minors fromtrying to buy, but it will keep them fromsucceeding," De Ruzzo said.

David Lichter, owner of the Broadway Market, apackage store just a block away from the Yard,said he was "basically embarrassed."

Su-Shin Chen, manager of Louie's Superette, aconvenience and package store popular with Dunsterand Mather residents, said she has installed anexpensive surveillance system to prevent heremployees from failing to card minors.