AON Consulting, the state of Delaware’s benefits consultant, mistakenly posted the Social Security numbers, gender, and birth dates of about 22,000 retired state workers on the Web two weeks ago, state officials and the company said yesterday.

According to a news report, the information was part of a request for proposal that AON had supplied to the state’s procurement website to solicit bids from insurance companies interested in providing vision benefits to state employees and retirees.

The information, which did not include the retirees’ names, remained on the Web from Aug. 16 to Aug. 20, when the breach was discovered, the report says.

Joe Micucci, a spokesman for AON, said the identifying information was supposed to be "randomized" before it was forwarded to the state. "In its place should have been different identifiers, obviously nothing associated with individuals," Micucci said, adding that the company is investigating what went wrong.

Brenda Lakeman, director of the Delaware Office of Management and Budget's statewide benefits office, said the identifying information was not included in earlier versions of the proposal that were reviewed by her office. It only appeared in the final version, but no one spotted the change.

Affected retirees are those on the state employees plan -- including teachers -- the judiciary plan, and the Delaware State Police plan, according to Catherine Kempista, spokeswoman for the Delaware OMB.

Aon began notifying potentially affected retirees by letter yesterday, the report says. Affected retirees will receive a free year of credit monitoring from Experian.