NEW YORK -- Former UFC welterweight/lightweight champion B.J. Penn has ended his retirement and will return to the Octagon, promotion president Dana White said Thursday.

"B.J. hit me about a month ago," White said during a news conference to promote UFC on Fox 3, which will be held Saturday night in East Rutherford, N.J. "I saw him in Sweden (during an April 14 event) and he wants to come back."

Penn announced his retirement inside the cage on Oct. 29 after dropping a lopsided unanimous decision to Nick Diaz at UFC 137.

"This is probably the last time you'll see me in here," a bruised and battered Penn said after the loss. "I want to perform at the top level.

"I've got a daughter, another daughter on the way. I don't want to go home looking like this."

Since calling it a career, however, the 33-year-old Penn has hinted at making a return.

Despite revealing his intention to fight again, White has neither set a date nor an opponent for Penn.

"That's up to him; whenever he's ready," White said of Penn's return date. "I don't ever push guys. Guys know when they are ready; guys know when they're ready to come back.

"Guys let me know when they are ready to fight."

The only certainty is that Penn will compete at welterweight.

"I'm done with telling (Penn) where to go as far as weight goes." White said. "The guy has handled himself in both weight divisions. You get to an age where cutting down to 155 doesn't make sense anymore."

Penn last held a UFC championship belt (155 pounds) in 2010. He relinquished that title on August 28 when Frankie Edgar defeated him via unanimous decision in a rematch.

After the loss, Penn returned to welterweight. Penn would fight three times in his 170-pound return, compiling a 1-1-1 mark during that span.

During his first fight back at 170 pounds, Penn KO'd fellow ex-champion Matt Hughes in the opening round on Nov. 20, 2010.

It was the third time Penn and Hughes had met inside the Octagon.

In their first meeting, Penn defeated Hughes on Jan. 31, 2004, to win the UFC welterweight title. The victory came in Penn's welterweight debut.

Hughes would retain the 170-pound belt with a third-round TKO of Penn during a rematch on Sept. 23, 2006.

Penn has a professional mixed martial arts record of 16-8-2.