AUGUSTA — About $6.5 million in voter-approved bonds for conservation projects that have been withheld by Gov. Paul LePage as a political bargaining chip have effectively expired. Land for Maine’s Future Director Sarah Demers told board members Tuesday that although the funds – first approved by voters in 2009 – don’t technically expire until November, there is no other opportunity for the bonds to be sold. Demers did not offer an immediate explanation of why the bonds can’t be sold in the next four months. The governor also has withheld another $5 million in bonds approved by voters in 2011, leaving the Land for Maine’s Future with just $2.2 million in cash to fund various projects. No votes were taken on any pending projects Tuesday because the Land for Maine’s Future board did not have a quorum of members present.