Via Philly Sports Daily:

Philly Sports Daily has learned that the Flyers have not come to an agreement with Bertilsson and he will be made available in the 2011 draft.

We weren't sure whether or not defensive prospect Simon Bertilsson would stay in Sweden with his club or come to North America on a contract with the Flyers organization, but either way, we expected Paul Holmgren and company to get their draft pick signed up with the organization on paper. 

They haven't, and since it's been three years since he was drafted, the Flyers have lost his rights. There was a 5 p.m. deadline to sign players such as Bertilsson, and the Flyers apparently didn't do that. He'll re-enter the 2011 draft in Minnesota later this month. 

Bertilsson, 20, was likely not ready to make the jump to North America, and he likely would have stayed another year with Brynas in Sweden even if he signed with the Flyers.

But now he'll likely never play for the Flyers, and for an organization with few prospects and even fewer draft picks, it's concerning to just lose one for nothing, even if it's a kid that's not yet NHL ready.

Bertilsson suffered from injury woes over the last few years, which could also play into the decision to not sign him. 

Further reading on Simon Bertilsson:

Jun 27, 2009: 2009 NHL Draft: Philadelphia Flyers select D Simon Bertilsson with 87th pick

Aug 11, 2010: Simon Bertlisson excels at international level

Sep 14, 2010: Simon Bertilsson Injured Again -  Will Miss Start of Season

Dec 12, 2010: Last shot at WJC for Simon Bertlisson