The show, which has produced high ratings for each of its first four episodes, initially committed to filming 13 episodes.

Its producers have turned O'ahu's Kualoa Ranch into a mysterious tropical island 1,000 miles from nowhere, complete with a menacing, unseen creature, a polar bear and lots of stubbly faces.

The extra nine episodes — network insiders call them the "back nine" — come during a week when rival network NBC cancelled "Hawaii," another action-drama filmed in the Islands.

Critics hated "Hawaii" and it suffered from low ratings. The network gave it the boot on Monday.

Both "Hawaii" and "Lost" competed for viewers during the same Wednesday night time slot.

A third TV series, "North Shore," also is filming in Hawai'i.

"It is always wonderful to hear when something does get the final word," said Walea Constantinau, commissioner of the Honolulu Film Office. "The business is very interesting and you never want to assume."

Although networks do not reveal what they are spending in Hawai'i, a drama like "Lost" typical contributes $1.5 million to $2 million per episode to the state economy, said Donne Dawson, state film commissioner for the Hawai'i Film Office.

"Obviously, given the news of earlier this week it is a solid shot in the arm for us," Dawson said. "Our mission is to get a successful series here for the long term. This is all in keeping with that."

Dawson was not surprised by the extra episodes.

"There are a lot of enthusiastic viewers who are following this show religiously," Dawson said. "This is really good news."