Redevelopers of Salt Lake City's downtown City Creek Center mall project said Wednesday that walking across Main Street in midair is crucial to the success of many of the retailers involved.

But the Salt Lake City Planning Commission says such a bridge has never been part of downtown's long-term plan and the panel will need more time and more details before deciding to approve it.

A sky bridge was one of several amendments officials from the Taubman Co., contracted by The Church of Jesus Christ of Latter-day Saints to come up with a plan for 20 acres of downtown property, asked the Planning Commission to consider making to the city's master plan.

"We're not here to posture with people," said Bruce Heckman, vice president of development for Taubman. "But developing a significant regional retail facility doesn't work without the sky bridge."

Taubman and the LDS Church plan to tear down the Crossroads Plaza and ZCMI Center malls to create a major new indoor-outdoor complex with retail, residential and office space. Demolition is set to begin in November, and the five-year project would conclude with a grand reopening in 2011.

However, Heckman said it would be difficult for Taubman to proceed with the City Creek Center project without the Planning Commission's approval for a "pedestrian connection" between the two sides of Main Street. He even called it a "threshold issue," saying that without the sky bride a redesign would be necessary.

The Main Street sky bridge concept has come up several times over the years, always meeting opposition.

Salt Lake City Mayor Rocky Anderson said in 2005 that he would stick to the city's master plan and fight any deviation, including a sky bridge, which he said would steal from the vibrancy of the city's streets. A 2003 Deseret Morning News poll, conducted by Dan Jones & Associates, found that 34 percent of Salt Lake City residents favored the idea of a sky bridge, while 31 percent somewhat opposed the idea and 20 percent strongly opposed it.

Taubman's Ron Loch, vice president of planning and design and structure, said the bridge could be "delicate and for the most part, transparent.

"We've had a lot of ideas, most of them including a transparent design that is complimentary to the personality of the city," he said. Local contextual images, such as the Eagle Gate on State Street, have helped foster structural ideas for the proposed sky bridge.