Google hired Wall Street veteran Ruth Porat to be its chief financial officer Tuesday, marking the first time a woman will join Google's C-suite ranks.

Like some companies in the technology industry, Google has struggled to promote women to the highest levels (jobs with "chief" in the title). Women make up 30 percent of Google employees and just 21 percent of those in leadership roles, according to a diversity report from the company last year.

Marissa Mayer and Sheryl Sandberg, former Google vice presidents, entered the executive suite only after they left for other firms. (Mayer is the chief executive of Yahoo, and Sandberg is the chief operating officer of Facebook.)

Early Google employee Susan Wojcicki is called the chief executive of YouTube, but she's listed as a senior vice president on Google's Web site. The firm's highest-ranking marketing executive is Lorraine Twohill, who is also a senior vice president. Of the 35 employees listed on the management team, three are women. Three women also comprise the company's 12-member board.

Porat comes from Morgan Stanley, where she has been one of the most powerful women on Wall Street for years.

She has some Silicon Valley connections. In more than two decades at Morgan Stanley, she served as its co-head of technology investment banking and worked on a number of major tech deals.

"Growing up in Silicon Valley, during my time at Morgan Stanley and as a member of Stanford's Board, I've had the opportunity to experience first hand how tech companies can help people in their daily lives. I can't wait to roll up my sleeves and get started," Porat said in a statement.