AUGUSTA — The state election practices commission Tuesday fined the campaign to allow large stores to open Sundays $250 for failing to register on time as a political action committee.

But the Commission of Governmental Ethics and Election Practices decided not to impose another fine that could have been as much as $1,000 for a related violation.

The Retail Federation of Maine is leading a referendum campaign to allow stores with more than 5,000 square feet of selling space to open for business on Sundays year-round. The question goes to Maine voters on Nov. 6.

The federation told the commission that it had failed to register as a PAC by the December 1989 deadline because it had misinterpreted the law.

Because it did consider itself an active campaign, the federation also failed to disclose complete campaign financial information to the state until after it was told violations had occurred.

While it voted to impose the $250 dollar fine, the commission waived the financial reporting fine because the law was changed earlier this year and the group had not received advance notice the reports were due.