LONDON, United Kingdom — Two more executives are leaving online luxury retailer Yoox Net-a-Porter Group SpA as Chief Executive Officer Federico Marchetti puts his stamp on the company about a month after it was created by a merger.

Ian Tansley, managing director of the Mr. Porter menswear brand, and Stephanie Phair, president of The Outnet discount site, will depart immediately, Milan-based Yoox Net-a-Porter said Wednesday in a statement. They follow Net-a-Porter founder Natalie Massenet, who quit in September. Both are being replaced by executives already at the company.

“Cultural clashes remain in our view the biggest risk” to the business, Citigroup Inc. analyst Mauro Baragiola said last week in a note. “While operations have been gradually converging, corporate cultures may have further to go.”

Yoox agreed in March to merge with Cie. Financiere Richemont SA's Net-a-Porter in an all stock deal. The new company, which was formed last month, has st week raised its estimate for annual cost savings to 85 million euros ($90 million) by 2018.

By Andrew Roberts; editors: Matthew Boyle, Paul Jarvis.