Alan McMenemy, was taken hostage with Moore and three other men in 2007. Moore was freed by his captors Wednesday.
Roseleen McMenemy, of Milngavie, told The Scotsman she was happy for Moore's family and was hopeful that her husband would be released soon.
"All I want to say is I'm delighted for Pauline (Sweeney, Moore's stepmother) and the rest of Peter's family," McMenemy said in an article published Thursday. "Hopefully, Alan will be home soon as well."
Whether McMenemy is alive is unknown, officials said. However, his wife said Moore's release has renewed her hope that her husband was alive, the newspaper said.
British Prime Minister Gordon Brown said he was "hugely relieved" by the news of Moore's release.
But, Brown said, "At this moment of celebration, we also remember the families of British hostages who have been killed in Iraq and elsewhere. And we pledge to continue to do everything we can to bring British hostages back to their loved ones, including the remaining hostage of the group in Iraq, Alan McMenemy. I demand that the hostage-takers return him to us."
The three other men, all bodyguards, were shot to death and their bodies returned to Britain.