The new shopping center on the 900 block of Market Street is the biggest and most ambitious retail development in San Francisco since the Westfield San Francisco Centre expansion just down the street a decade ago.

At 250,000 square feet on six levels, it offers as much space as five football fields. It cost $150 million to build. It has 167 parking spaces, 18-foot ceilings, multiple loading docks, freight and passenger elevators, dramatic scissoring escalators and a towering glass curtain wall front that looks straight up Mason Street to Nob Hill.

But there’s one thing the big glass box doesn’t yet have: tenants.

“We’re pretty picky,” said Chris Maguire, chief executive officer of developer Cypress Equities.

With workers scurrying to meet a November completion deadline, Maguire, who is based in Dallas, was in town this week to check out the building’s progress and work on a rebranding and repositioning campaign he hopes will make the project a centerpiece in the resurgence of the Mid-Market neighborhood.

To start with, Cypress Equities has renamed the project, dropping “Market Street Place” in favor of 6X6, a reference to both the building’s six floors of retail and its location near Sixth Street. It has also replaced its in-house leasing team with a local group from Cushman & Wakefield, led by top broker Kazuko Morgan.

While many developers might be inclined to play down the Sixth Street association, with its residential hotels and seedy street activity, Morgan said Cypress decided to embrace the grit.

“If you want everything to be perfectly clean, you might as well move to L.A.,” she said. “Market Street Place is generic. What does that mean? We felt strongly that we have something that is cool and exciting and appeals to younger people. This is urban. You’re at Sixth Street. Why not own it? Why not be proud of it?”

The rebranding comes at a time when Mid-Market seems to be simultaneously booming and languishing. It’s now been nearly five years since the neighborhood revival kicked into gear with the arrival of Square, Uber, Twitter, Yammer and other tech companies. Market Street’s sidewalks are busier than they were. More than 3,000 housing units have been added near Market Street between Van Ness Avenue and Fifth Street.

Within a block of 6X6 there are thriving businesses like Huckleberry Bikes, Equator Coffee, David Rios Chai and Popson Burgers. The co-working group WeWorks is opening its second location nearby.

Yet other projects have been slow to come to fruition. Two hotels to be built at Seventh and Market — Yotel and San Francisco Proper — are a year or more behind schedule. The restored Hibernia Bank at Jones and Market remains without a tenant.

Five years after it was proposed, developer Joy Ou’s massive redevelopment across the street from 6X6, which is to have 242 condominiums and a 232-room hotel, is still working its way through the approval process and won’t open until 2019, at the earliest. Another 1,500 housing units are planned for Mid-Market, but most are still in the approvals stage.

“So many projects are entitled but have taken longer than expected,” Maguire said. “That has been the challenge — convincing retailers that the Mid-Market story is real.”

So what will 6X6 be like and what sort of tenants might it attract?

Morgan and Maguire would not name individual retailers but said that they are in talks with multiple fashion-forward brands not currently in San Francisco (think Topshop and Primark). They are talking to home goods retailers, grocers and, against all odds, bookstores, which are doing well again.

The fifth floor will likely include multiple restaurants and cocktail lounges, as well as a mom-and-pop food hall.

Morgan called 6X6 a multilevel retail, food and entertainment center — not a shopping mall.

“If you go to Hong Kong or Tokyo, there are so many of these cool retail developments being built,” she said. “Just not in the United States.”

Over the last four years several retailers — including Target and Saks Off 5th Fashion Outlet — looked at 6X6 only to choose existing Market Street spaces ready for occupancy well before the new building. Other deals that fell through included a 130,000-square-foot lease with the struggling JC Penney and a smaller deal with the now-bankrupt Golfsmith.

The delays “have been 100 percent in our favor,” Morgan said. “Anything we would have done three years ago, today we would have been like ‘What the hell were you thinking?’”

Julie Taylor, retail specialist with Colliers International, said that 6X6 will draw patrons if it attracts retailers that offer discounts and values. She said that Nordstrom Rack and Saks Off 5th, both located on the east end of the 900 block of Market Street, are doing extremely well.

“It’s the logical complement to the high street retail and fashion retail offered in Union Square,” said Taylor. “You need a powerful magnet to draw customers from the Westfield and the 800 block of Market Street. The consumer needs a reason to walk a half of a block to the west, and the most powerful draw is a value proposition.”

But Matt Holmes, a broker with Retail West, predicted the project would snag Union Square or Powell Street shops looking for more affordable rent. He said he could see a strong entertainment component — several national companies that develop urban bowling centers are looking for space and would be a good fit.

“At the end of the day, 6X6 needs to be cheap,” said Holmes. “They need to be the safe haven for tenants that don’t want to give up on San Francisco yet.”

The move away from the traditional shopping mall concept is wise, said retail consultant Doug Stephens.

“Malls are going bankrupt, so it’s good they don’t want to be a mall,” he said. “We are moving to the point where the mall itself is the anchor. People go to the mall to go to the mall, not to visit one business. It has to be about food and entertainment and lifestyle. That has to be the draw.”

Even without tenants one thing will open in November: the two-level underground parking garage.

“I think we would be panicking if we had no interest from tenants — but that is not the case,” Maguire said. “If we walk this building a year from now and it still looks like this — then you can write the ‘empty building’ story.”

J.K. Dineen is a San Francisco Chronicle staff writer. Email: jdineen@sfchronicle.com Twitter: @sfjkdineen