SEC Chief Schapiro Is Leaving; New Chairman Chosen

(We updated the top of this post at 11:50 a.m. and 12:15 p.m ET):

Moving quickly after the announcement that Securities and Exchange Commission Chairman Mary Schapiro is leaving on Dec. 14, the White House just said that President Obama has designated SEC Commissioner Elisse Walter to be her replacement.

In a statement, the president says:

"I want to express my deep gratitude to Mary Schapiro for her steadfast leadership at the Securities and Exchange Commission. When Mary agreed to serve nearly four years ago, she was fully aware of the difficulties facing the SEC and our economy as a whole. But she accepted the challenge, and today, the SEC is stronger and our financial system is safer and better able to serve the American people – thanks in large part to Mary's hard work.

"I am also pleased to designate Elisse Walter as SEC Chairman after Mary's departure. I'm confident that Elisse's years of experience will serve her well in her new position, and I'm grateful she has agreed to help lead the agency

According to The New York Times' DealBook blog, "Ms. Walter's appointment does not require Congressional approval because the Senate previously confirmed her as a commissioner. Eventually, the White House is expected to nominate another agency chief, according to a person briefed on the matter."

Walter, a Democrat, was first appointed to the commission by President George W. Bush.

Our original post:

The Securities and Exchange Commission just confirmed that Chairman Mary Schapiro is stepping down on Dec. 14.

That word follows a report earlier this morning from The New York Times, which broke the news.

Her departure is not a surprise. Last week, The Wall Street Journal wrote that "current and former SEC officials have predicted" Schapiro would soon step down. The Journal also reported that the Treasury Department's under secretary for domestic finance, Mary John Miller, "is under consideration" to be the next SEC chairman.

In the SEC statement, Schapiro says:

"It has been an incredibly rewarding experience to work with so many dedicated SEC staff who strive every day to protect investors and ensure our markets operate with integrity. Over the past four years we have brought a record number of enforcement actions, engaged in one of the busiest rulemaking periods, and gained greater authority from Congress to better fulfill our mission."

She became chairman in 2009.