The sister of Terry Anderson, marking his sixth anniversary as a hostage in Lebanon, said Friday she was very optimistic that he and at least 11 other Westerners held captive would be released.

Peggy Say, who has campaigned tirelessly for Anderson's release, said that conditions for the release of Western hostages in Lebanon were improving.She said her optimism stemmed from the attitudes of Syria and Iran, thought to have the most influence with the hostage-takers, as well as President Bush's stated commitment to freeing them.

"I think the hostage issue is where we've wanted it to be for six years and that's a public priority" for Bush and Secretary of State James Baker, she said in an interview on NBC's "Today" show.

She expressed belief that Syria, which controls much of Lebanon with 40,000 troops under a 1976 Arab League peacekeeping mandate, was doing "absolutely all it can" to free the hostages.

"And Iran seems in a mood to concentrate - or to cooperate - and I think that's what it's going to take to bring this to an end," Say added.

Anderson, chief Middle East correspondent for the Associated Press, was kidnapped in West Beirut on March 16, 1985. Islamic Jihad, a pro-Iranian Shiite fundamentalist group, claimed responsibility.

A Capitol Hill ceremony to honor the hostages and remember nine others believed to have died in captivity was scheduled for Friday by No Greater Love, a Washington-based humanitarian group.