WETHERSFIELD, Conn. — More than 8,000 vehicle owners in Connecticut missed their car registration renewal deadlines last February because they didn't receive a renewal notice due to a computer glitch, the Department of Motor Vehicles announced Friday.

The registrations were flagged for renewal in the department's computer system but notices to about 8,340 vehicle owners were never printed. The DMV said the mistake was discovered during an ongoing review of its troubled computer upgrade, launched last summer.

The department said it's now sending out revised renewal notices. Meanwhile, drivers are being urged to carry the notice in their vehicle to show police, if stopped.

"As part of our continuing analysis of our computer issues, we came across and verified today the extent of it. We are notifying these customers right away," said DMV Commissioner Michael Bzdyra. "I apologize for the inconvenience this causes the affected customers."

Vehicle owners who receive the new notices will have until Sept. 30 to complete their registration renewals. Any late fees associated with the overdue notices will be waived. However, renewals cannot be done online.

The DMV is providing an envelope with the notices to help customers avoid having to visit a branch office.

While fixes have been made since February, when the registration renewal problem occurred, Bzdyra said the latest situation is unacceptable. He said it will be part of the agency's discussion with 3M, the private vendor originally hired to upgrade the computer system.

In April, DMV notified 3M it was exercising a contract option and wouldn't go forward with the company for the third phase of the project. Bzdyra reiterated Friday that DMV still plans to hold the company's "feet to the fire to fix everything that's wrong with this system." A 3M spokesman has said the St. Paul, Minnesota-based company remains committed to meeting its obligations to Connecticut.

Bzdyra announced last month DMV planned to undertake an extensive review of day-to-day operations to reduce customer wait times, another problem that has dogged the agency since the computer upgrade. That project is expected to take six months to complete.