A state task force is recommending that the Legislature extend a law that allows the Hawaii Superferry to continue operating as it prepares an environmental impact statement.

The controversial law, known as Act 2, was passed by state lawmakers during a special session last year to allow the Superferry to operate without an EIS until the summer of 2009 while the study is completed.

Now, the 13-member Inter-Island Ferry Oversight Task Force says the law's expiration date should be repealed.

"In order to ensure that there is a comprehensive public comment period and the ACT 2 EIS is completed, the (task force) recommends that the repeal date of ACT 2 be repealed," said a report from the task force.

Environmentalists have sued the state to overturn the law, saying it amounts to unconstitutional special legislation that benefits the Superferry alone. That case is pending before the state Supreme Court.

State Auditor Marion Higa also criticized the law in a report this month. She called it a "worrisome precedent" that places the interests of a single company ahead of the state's environmental, financial and public safety responsibilities.

The state has argued that lawmakers and Gov. Linda Lingle were acting in the public interest to preserve an alternative mode of transportation for the Islands.

Mike Formby, deputy director of the state Transportation Department and a member of the task force, said that some members opposed eliminating the expiration date.

But he said a majority felt that other ferry operators who may want to enter the Hawai'i market should be allowed to take advantage of the law.

Robert Harris, director of the Sierra Club's Hawai'i Chapter, one of the groups that sued the state, said a repeal of the law's drop dead date "would give the Superferry a free pass while the review is being conducted."

"The intent of the bill was to force an environmental review by a certain date," he said.

The 27-page report, which was made public Monday, also disclosed that the state's costs relating to the Superferry have risen from $40 million to $44.7 million.

Much of the $4.7 million increase is the cost of conducting an EIS and for other ACT 2 related costs, Formby said.

In an e-mail, Superferry officials praised the task force's efforts, saying their report along with data collected during nine months of operations "resulted in an increased understanding of Hawaii Superferry's operations and its contribution to our community."

ACT 2 was passed by the Legislature after the Hawai'i Supreme Court ruled in August 2007 that the state should not have exempted the Superferry project from environmental review, which led to legal challenges on Maui and public protests on Kaua'i that temporarily halted ferry service.