UPDATE: "Timely, fair, and effective registration solution" for the 15,000 remaining slots will be announced on February 28th," official says ...

If you haven't signed up for the 2013 Bank of America Chicago Marathon, it could stay on your to-do list until at least Sunday.

Marathon officials say technical problems likely will keep registration shut down through the weekend. Organizers on Tuesday decided to temporarily suspend registration after website issues sidelined hundreds of interested participants.

"We do not plan on reopening registration within the next two days," race director Carey Pinkowski said in a Tuesday afternoon statement.

Many ran into problems registering for the Oct.13 race shortly after registration opened at noon on Tuesday, though Pinkowski said many runners were able to successfully register before race officials suspended that portion of the site. Pinkowski said about 15,000 open spots remained.

According to a message posted on the web site, registration provider Active.com is working to resolve system-wide technical issues.

"We apologize to the Chicago Marathon and to all runners. The entire ACTIVE team is working tirelessly to ensure that we remedy all of the errors," Active.com officials said in a statement.

"Before we re-open registration, we need to make sure all technical issues are permanently resolved. We will provide ample notice regarding when the registration process will re-open," Pinkowski said. " We sincerely appreciate the enthusiasm and support for the event."

Forty-five thousand participants will be allowed in the race, a number that is usually reached within a few days.