By John Revill 

Natalie Massenet was a fashion journalist early in her career. That experience is evident in Net-A-Porter, the online clothing retailer she founded that will be folded into Italy's Yoox SpA.

Ms. Massenet, who got the idea for Net-A-Porter while researching clothing for shoots, laid out her website to resemble a fashion magazine, like Vogue. That would make it simpler for online visitors, which now number 2.5 million a month, to click on an outfit from a website that looks like a magazine.

On Tuesday, Net-A-Porter took a step toward increasing its readership. Swiss luxury giant Cie. Financière Richemont SA, which bought the bulk of Net-A-Porter in 2010, said it was combining with Yoox to create one of the world's largest companies dedicated to online luxury retailing.

Richemont didn't make Ms. Massenet available for an interview.

Ms. Massenet, a Los Angeles native, worked as a model in Japan before starting her career as a journalist at Women's Wear Daily and Tatler. The mother of two, who holds both U.S. and U.K. citizenship, set up Net-A-Porter in June 2000.

Since then Net-A-Porter has expanded to include The Outnet.com, a fashion outlet, and MrPorter.Com, one of the first global online sites for menswear.

The company now employs 2,500 people in London, New York, Shanghai and Hong Kong.

In January 2013, Ms. Massenet was named chairman of the British Fashion Council, a body set up to promote British fashion. She was made a Member of the Order of the British Empire for services to the fashion industry in 2009.

Write to John Revill at john.revill@wsj.com

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