PORTLAND, Maine — A glitch regarding the city Comprehensive Plan has forced the City Council to delay a vote on rezoning land at 58 Fore St. until June 1.

Mayor Michael Brennan announced at the start of Monday’s council meeting that the plan must be re-certified by the state to assure consistency with the Growth Management Act.

Later in the meeting, councilors unanimously approved postponing a public hearing and vote on the zoning to June 1, although it could be considered sooner if state officials quickly re-certify the plan that was last approved in 2003.

The delayed vote on rezoning 10 acres surrounding the Portland Co. Complex, a state-owned right of way, and underwater acreage capped a week of discussion about the potential economic impact of developing the property now owned by developers Jim Brady, Casey Prentice and Kevin Costello.

Jeff Levine, director of Planning and Urban Development, said the need to re-certify the plan is part of a 2008 policy instituted by the former State Planning Office. It was discovered by city staff during research into the zoning request by the Portland Co. property owners, who do business as CPB2.

The lack of certification of the plan, which includes the Eastern Waterfront Master Plan considered by CPB2 as a template for zoning and development, does not mean the city has to halt planning and zoning, Levine said.

“There’s nothing about the state certification process that requires we freeze everything,” he said, adding he thought it best to hold off. The re-certification request was sent late last week.

In a press release, Brady said he was disappointed, but understands the need to wait.

“We support the desire of the city to make sure that when a zoning ordinance is amended, that it is done so in accordance with a properly certified Comprehensive Plan,” he said.

The request to convert the complex of 12 buildings that date to the 1840s to a zone allowing mixed residential and commercial uses was recommended unanimously by the Planning Board on Feb. 24. It had a first reading by City Councilors on March 16.

The property has also been nominated for designation as a city historic preservation district, and on April 1, the Historic Preservation Board heard the results of a city-commissioned report by Resurgence Engineering on current conditions and rehabilitation possibilities.

“In our opinion, it is possible to address the identified structural and building envelope conditions in ways that retain each building’s historic character and that are feasible from a cost perspective,” engineer Alfred Hodson III concluded.

Hodson said his report drew many of the same conclusions as one prepared by engineer Paul Becker and commissioned by CPB2.

“Our two reports were comparable. There is a bit of a difference of opinion on possibilities,” he said.

The reports describe cracked exterior masonry, a need to shore up interior structural supports, and rot in buildings constructed through the latter 19th century and up to 1918. The buildings extend across land bordered by Fore Street and are also built into a street retaining wall.

“We are trying to find a way to save eight of the 12 structures,” Prentice said Monday, but added the cost of preservation is a factor in how the property will be developed.

On April 2, economist Charles Lawton of Planning Decisions presented a report projecting an $85 million valuation increase because of development at the property. He said it would create more than 200 jobs and almost 400 housing units.

The new tax revenue could amount to $1.5 million, and have a regional impact of $254 million during development and a residual impact of $38 million, Lawton found. The regional impact would support more than 1,700 jobs during development and 325 residually, he concluded.

The basis for comparison is a 10-acre section of the Old Port bounded by Exchange, Commercial, Pearl and Middle streets, Lawton said.

“The idea is to take something that is well-known and used and get its values and apply it to another area,” Lawton said, even though CPB2 has not created a definitive site plan for development.

Lawton said his findings are speculative, but intended to create discussion on how an underused property could be a benefit to the city and region.

“It is really the story of some new economic activity,” he said. “The most central issue is to get people to imagine an alternative in the future.”