JUNEAU — Business leaders in Fairbanks last year issued a show of support for a proposed railroad track extension that would occur hundreds of miles away.

The plan’s backers list Fairbanks as one of the big potential beneficiaries. They say it would make Alaska’s coal resources far more competitive on world markets, could turn Fairbanks into a major cement production center and would significantly improve the profitability of surrounding resource development.

Rick Mystrom, a project consultant and former Anchorage mayor, suggested thinking of Fairbanks, Anchorage and communities in between as joint beneficiaries if the 30- to 45-mile extension is built to Port MacKenzie, on Cook Inlet west of Wasilla.

Mystrom told state lawmakers Wednesday the proposed $250 million railroad project comes at the right moment: Times are tough and labor costs have fallen, meaning the state could invest cheaply now in major transportation infrastructure to support jobs in the short run and help diversify Alaska’s economy for the long haul.

“I would encourage the Legislature to use capital spending now” for the project, he told the Senate Resources Committee. “This is one of the projects that can make a big difference.”

The project would connect railroad tracks to Port MacKenzie, shaving off 140 miles of distance — and potentially cutting freight costs — from exported bulk commodities such as coal or limestone departing Southcentral by sea.

Representatives from a slate of groups involved with the project, led by the Matanuska-Susitna Borough and the railroad, visited Juneau this week seeking major financial support.

Pat Gamble, the railroad’s CEO, told lawmakers by phone that the Legislature previously cleared the railroad to use bonds for the work. But Mystrom and Matanuska-Susitna Borough officials are pushing for direct state investment now, saying the project is ready to go and could be built in three years.

The request faces an uncertain climate in Juneau. Many lawmakers have called for increased capital spending, but Gov. Sean Parnell has sought to hold a lid on the state’s construction budget.

Sen. Joe Thomas, D-Fairbanks, said Port MacKenzie has the capacity to expand in the future if needed, making it a good spot for investment. But Thomas, a member of the Senate Finance Committee, said the project’s sponsors have an uphill battle in the capital

Rep. Mike Kelly, R-Fairbanks, said he needs more details before speculating on whether legislative finance committees might support the request.

“Generally I’m favorable. The port (project) has some clear benefits to the Interior,” said Kelly, a member of the House Finance Committee.

A $10 million environmental study of the project is finished and John Duffy, manager for the borough, said a federal transportation board could issue draft approval as early as next month.

Even slightly lower freight costs might mean a lot to the profitability of mining in the Interior. The project could carve $3 per ton from the price of hauling coal and minerals by train, according to the group. It also could make it far more profitable to start new mines along either side of the railroad’s existing track, they said.

The push follows a big year for one of the railroad’s big private-sector customers, Usibelli Coal Mine. The mine’s annual exports, which have normally accounted for about one-third of its production, almost tripled from 2007 to 2009 to more than 800,000 tons, partly because of increased shipping to South America.

Steve Denton, a vice president for Usibelli, said his company has big questions about the project and its touted benefits. He said it generally costs more to ship product from Cook Inlet, given higher docking costs and longer waiting times, than from the bulk commodities port at Seward. But a Port MacKenzie rail connection could be a summertime complement to the route to Seward, which suffers from high traffic problems during tourist season, Denton said.

“I think that’s where we see some real opportunity with Port MacKenzie,” he said of complementary bulk ports.

The project could translate into hundreds of millions in value to coal operators, new mines and potential owners of a cement plant, and more through other related business activity, according to a 2008 analysis by the Institute for Social and Economic Research at the University of Alaska Anchorage.

“These are extraordinarily good returns on an infrastructure investment in Alaska,” the institute wrote in the analysis’ summary.

Duffy said construction could create or support 3,000 jobs and new mining development could support the same figure in the long haul.

“We believe this project offers tremendous economic opportunity to the state of Alaska,” Duffy said Wednesday.