(Reuters) - Coveted invitations to New York's Fashion Week will be a little easier to snag next month, with the unveiling of a public runway show designed to inspire shoppers to add to their wardrobes for fall and winter.

Marc by Marc Jacobs. Backstage fashion at presentation of A/W collection 2010 in New York

While designers will be showing their collections for spring and summer 2011 exclusively to retailers and the media, the September 7 public fashion show to kick off Mercedes Benz Fashion Week will remind consumers of the styles they can buy now, organizers said on Wednesday.

The show is a new addition to the second annual "Fashion's Night Out," a retail initiative by U.S. Vogue editor Anna Wintour that aims to get people shopping as the United States struggles to shake off its worst recession in decades.

"The fashion business is big business here in the Big Apple," Mayor Michael Bloomberg said at a news conference announcing details of "Fashion's Night Out," which he said is "offering consumers more opportunities to see all the city's retailers and designers have to offer and helping strengthen our economy in these tough times."

In New York, fashion is the second largest industry behind finance. The city is home to more than 800 fashion companies, employing 175,000 people and generating $10 billion in wages.

"Fashion's Night Out" attracted thousands of shoppers last year and retailers are hoping for a repeat performance, as the country struggles to shake off its economic woes.

U.S. consumer sentiment hit its lowest level in nine months in July, according to Thomson Reuters/University of Michigan's Surveys of Consumers, and any renewed weakness in consumer spending -- it accounts for two-thirds of the U.S. economy -- could cast a shadow on an economic recovery.

The "Fashion's Night Out" show, the largest public runway show to be held in New York City, will feature trends for fall and winter chosen by Vogue, and the more than 1,500 available tickets start at $25. On September 10, nearly 1,000 retailers plan to stay open until 11 p.m. to persuade people to spend.

Designer Marc Jacobs said "Fashion's Night Out" celebrates "a social ritual that people enjoy."

"I was really happy to see people not in front of a computer screen and adding to their cart but actually getting out and interacting with each other and being out on the streets of the city," Jacobs said of last year's event.

The "Fashion's Night Out" event is also part of a bid by the fashion industry to diffuse consumer confusion surrounding the semi-annual Fashion Week in New York, which is followed by fashion weeks in London, Milan and Paris.

Designs for next spring and summer will appear on the runways during New York's Fashion Week, from September 9-16, that will not be available to consumers for six months or so, while most shops are filled with clothes for fall and winter.

"We've focused the show on the trends we thought were most important, so that no matter what their style or budget shoppers will have a source of inspiration," Wintour said in a statement.

(Additional reporting by Ellen Wulfhorst, editing by Paul Simao)