ANNAPOLIS // Prince George's County elections officials failed to provide enough voting machines at two-thirds of the county's precincts as required by law on Election Day, the state's elections chief said.

In a letter sent to the county's Board of Elections last month and released publicly Friday, State Elections Administrator Linda H. Lamone wrote that Prince George's provided too few voting machines at 133 of the county's 206 precincts. State law requires one machine for every 200 registered voters.

Long lines were common Nov. 7 at many polls in the county, and some voters waited until midnight.

At the University of Maryland, for example, one voting station was supposed to have 12 machines but was provided with four. Students did not finish voting until 2 1/2 hours after the polls closed.

In her letter, Lamone wrote that the insufficient number of machines was "most likely the primary cause" for the lines. She also asked the county for an explanation.

In response, Prince George's elections officials acknowledged that they failed to provide enough machines in many precincts. They also said long lines were compounded by a lengthy ballot that included 13 local questions.

The county's interim election administrator, Robert J. Antonetti Sr., said the machine error occurred because an employee missed a summer deadline to provide updated voter registration information to the state.

As a result, machines were allotted using voter registration data from 2004. Antonetti said the employee no longer works for the county.

"It's extremely disappointing," said Board of Elections President S. John di Stefano. "We just hope to heck it never happens again."