Once the booming manufacturing area where consecutive waves of immigrants made up the engine of the American apparel industry, the garment district is now one of the most depressed parts of Midtown, and area leaders are pressing for changes in an attempt to revive it.

With most textile manufacturing relocated overseas, business and property owners are seeking zoning changes that would preserve some of the area’s roots while refashioning it as a 24-hour-a-day, seven-day-a-week community.

The city is also studying options that would add flexibility for development and use of space within the Garment Center Special District, which roughly encompasses the area between 34th and 40th streets and Sixth and Ninth avenues. Under current restrictions, residences and hotels are not permitted in about half of the district, particularly on side streets, and conversion to office space from manufacturing is severely restricted.

A plan advocated by the local business improvement district, called the Fashion Center, envisions a livelier mixed-use neighborhood on the model of SoHo or the Lower East Side.The executive director of the Fashion Center, Barbara Randall, said the plan would stop an exodus of young designers to other parts of Manhattan and keep the fashion in the garment district.

“Let’s figure out how much space manufacturing needs in 2006, not 1960 or 1970,” Ms. Randall said.

The plan envisions limiting the amount of space devoted to production, and bringing attractive ground-floor retail to the area, particularly boutiques and small cafes.

Lower floors of mid-block buildings, Ms. Randall said, could be dedicated to production,and the top floors, which include the loft-like spaces that have been so popular on the residential market, would be converted to apartments.

So far, Ms. Randall said, “The city is so reluctant to even work with us on some kind of plan.”

A spokeswoman for the city’s Department of Planning, Rachaele Raynoff, said that the department is studying the issue but would not make any changes that cost the city jobs.

The special garment zoning district was created in 1987 with the goal of keeping apparel production in Midtown and as a way to curb rapidly declining manufacturing employment within city limits. For many years, the zoning was under-enforced, and much of the space was illegally converted into office space. Based on a Bloomberg administration initiative in 2005, enforcement has been stepped up.

Ms. Randall said the newly increased enforcement is not having the right effect.

“Zoning has not been a preserving mechanism,” she said. “Zoning didn’t stop the global pressures. If labor is cheaper in China, then it’s cheaper in China.”

She said that about 9 million square feet of space is currently reserved for production, and she would like to see that number reduced to about 1.5 million square feet.

Data provided by a nonprofit that aims to keep the garment business in New York, the Garment Industry Development Corporation, showed that in 2005, 175 manufacturing firms employed about 1,700 people within the boundaries of the traditional garment district.

A project manager for the nonprofit, Magda Aboulfadl, is surveying all the district’s buildings to get an accurate idea of the current uses and how much is currently devoted to manufacturing.

“Every factory I’ve asked, they say they have to be there, or else they will go out of business,” Ms. Aboulfadl said. “They say it’s a different business that goes on in Brooklyn than here.They have to be where they are because of their business model and their customers.”

She added that most of the production that remains is for high-end fashion products that could not be made overseas.

“The really high-end stuff, if it could be done in China, it would already be going on in China,” she said.

Still, Ms. Aboulfadl said her organization would support a proposal that would allow greater development flexibility in exchange for a guarantee that garment manufacturing would permanently occupy 1.5 million square feet of space in the district. She said, however, that the changes would be difficult to implement.

A 2003 report by the Real Estate Board of New York, which supports a change in the zoning, said that the garment district’s zoning is costing the city millions of dollars each year in lost tax revenues because the regulations lower the value of buildings. It said the special district rules have resulted in lost income for building owners, and failed to retain manufacturing jobs, which are plummeting.

The president of the economic development consulting firm Appleseed, Hugh O’Neill,did a study on the area in 2003 and said a zoning change would not necessarily lead to the development of exclusively luxury residential units to replace factories. He suggested that a light manufacturing zone would encourage other activities that have already taken root in the area, such as the performing arts.

“Removing the special zoning doesn’t necessarily mean the fashion industry will disappear from the area. Would it accelerate the decline of manufacturing in the area? It might, but on the other hand it doesn’t seem to have much of a future anyway,” Mr. O’Neill said.