* Led probe into Google that ended with mild reprimand
* Passionate about drugmaker "pay for delay" cases
* Two current commissioners among those seen in running
By Diane Bartz
WASHINGTON, Jan 31 (Reuters) - The chairman of the Federal Trade Commission, Jon Leibowitz, said on Thursday he will step down in mid-February after a tenure famous for a probe of allegations that Google manipulated search results that resulted in a mild reprimand for the technology company.
Leibowitz, a Democrat who had led the agency since 2009, told Reuters he will leave in the middle of February and take some time off before beginning work in the private sector. He does not yet have a new post.
The four people considered most likely to replace him include fellow commissioners Julie Brill and Edith Ramirez and Howard Shelanski, the director of the FTC's Bureau of Economics.
The fourth potential candidate is Philip Weiser, a veteran of the White House and Justice Department, who now teaches law at the University of Colorado in Boulder.
As current commissioners Brill and Ramirez would not face confirmation by the Senate.
In the world of high-tech, Leibowitz will be known as the regulator who took on Google, the search engine giant, but did not win the tough settlement that many hoped for.
Leibowitz, 54, also pursued brand name pharmaceutical companies who engaged in so-called "pay for delay" with generic drugmakers, and made online privacy an issue, pushing unsuccessfully for companies to allow consumers to choose for themselves whether they wanted to be tracked online.
Under Leibowitz, the agency also went after a long list of small-time scam artists who failed to deliver on promises to consumers to lower credit card interest rates or stave off foreclosures.
THE GOOGLE FIGHT
The FTC's most public fight during Leibowitz's chairmanship ended with a less than a bang.
Leibowitz had pushed hard for the FTC to investigate allegations that Google manipulated its Web search results to hurt rivals, among other offenses.
In a highly publicized trip to California's Silicon Valley, he announced that the agency had hired a crackerjack litigator to take on the search giant - racheting up expectations that the probe would end in litigation.
But in early January, Leibowitz announced that a much smaller deal had been reached with the search giant - one that ended the practice of "scraping" reviews and other data from rivals' websites for its own products. Google also agreed to no longer request sales bans when suing companies which infringe on patents that are essential to ensuring interoperability.
Leibowitz acknowledged at the time that that there would disappointment with the FTC decision. "Even though people would like us to bring a big search bias case, the facts aren't there," he said.
TAKING ON DRUG COMPANIES
The issue that has perhaps been closest to Leibowitz's heart has been fighting deals that brand-name drug companies make with generic manufacturers in order to stop them from bringing out a cheaper version of marquee drugs.
The FTC says that 127 such deals reached between 2005 and 2011 cost consumers, insurance companies and the government $3.5 billion annually.
The arrangements have vexed antitrust enforcers for more than a decade.
The FTC has thus far had mixed success in fighting them but the issue could be coming to a head.
In December, the U.S. Supreme Court agreed to decide whether Solvay Pharmaceuticals Inc, now owned by Abbott Laboratories, acted illegally when it paid three companies not to manufacture of generic versions of AndroGel, a treatment for men with low testosterone.