Washington ? Michael Powell has tackled thorny issues involving media ownership rules, phone competition and the Internet as the nation’s top communications regulator, but a “wardrobe malfunction” got him the most attention.

Powell announced Friday that he will step down in March as chairman of the Federal Communications Commission, culminating a four-year tenure in which the Republican-controlled agency championed a generally pro-business agenda and dramatically stepped up enforcement of broadcast indecency standards.

Powell’s departure had been expected, though the timing was a surprise. In an interview, Powell said he reached his decision over the holidays and looked forward to vacationing with his wife and two sons, ages 16 and 10.

Powell may be best known by the public because of the FCC’s harsh response to Janet Jackson’s “wardrobe malfunction” during last year’s Super Bowl halftime show. But Powell said he was proud of his efforts to promote new technologies like high-speed Internet access and digital TVs.

“Our principal passion is that we believed we should work hard to get the law right to stimulate innovative technologies that put more power into the hands of consumers,” said Powell, son of Secretary of State Colin Powell, who also is leaving his job. “I felt very comfortable that we achieved most of what we set out to do.”

Though he clashed often with the two Democrats on the FCC, all five commissioners have been united in seeking harsher penalties for violations of broadcast indecency standards.

The FCC has five members, and the party in power at the White House holds three seats. Powell was nominated by former President Clinton to a Republican spot on the then-Democratic dominated commission in 1997. Bush made him chairman in 2001.

There was no immediate word on a successor.