Women’s media startup Sugar said today it has raised $15 million in a new round of funding to expand its brand into new markets.

The San Francisco-based company runs celebrity news site PopSugar.com and said it plans to use the money for brand extensions, acquisitions and international growth as part of a plan to become the world’s largest media company focused on women’s lifestyles. The five-year-old company said it has a global audience of more than 20 million unique visitors a month. Other sites include ShopStyle.com, PopSugarCity.com, and Fashionologie.com.

The investment was led by Institutional Venture Partners with participation from original investor Sequoia Capital. To date, Sugar has raised $46 million.

Rivals include Yahoo, which has expressed an interest in acquiring Sugar. But husband-and-wife co-founders Brian and Lisa Sugar have remained independent. Sugar was previously affiliated with NBC Universal, which had put $10 million into the company, but it bought back its stake in 2009 and received a $16 million third round of funding at the time from Sequoia.

Sugar has 190 employees and operations in the U.S., Europe, Japan, and Australia. Brian Sugar, chief executive, says the company’s users drive more than $250 million in commerce to its partners. He also said the company was profitable in 2010. Rivals include other ad-supported community lifestyle sites targeting women such as Glam Media.