WASHINGTON – In an attempt to reclaim the spotlight from his Al Qaeda rival and putative boss Osama bin Laden, Abu Musab al-Zarqawi, America’s chief nemesis in Iraq, boldly emerged from the shadows in an unprecedented videotape released yesterday.

Apparently shot last Friday afternoon, the 34-minute color video was rushed out onto radical Web sites and messages boards around the world yesterday – less than 48 hours after Mr. bin Laden’s latest audiotape aired on Al-Jazeera, the Qatar-based television network.

Mr. Zarqawi is not believed to enjoy the same quality of relationship with Al-Jazeera producers as Mr. bin Laden and, like many upstarts, he turned instead to the Web.

Mr. Zarqawi and the high command of Al Qaeda, led by Mr. bin Laden and his Egypt-born deputy, Ayman al-Zawahri, have long had a rocky relationship. Mr. Zarqawi was only brought into the international terrorist network after he proved his loyalty to radical Islam by enduring five years in Jordan’s maximum security prison for terrorist acts, and after Saif al-Adel, the head of the military wing of Al Qaeda, personally vouched for him in Afghanistan that same year. Even then, Mr. Zarqawi was told to set up terrorist training facilities in Herat, Afghanistan – hundreds of miles from other Al Qaeda camps in the eastern foothills near Kandahar.

Now it appears an intense rivalry is emerging between Messrs. Zarqawi and bin Laden. A letter from Mr. bin Laden’s deputy, intercepted in 2005, entreated the Jordanian to send money to his masters. Other captured letters and an e-mail sent to a London-based radical cleric demonstrate the Al Qaeda leadership’s increasing impatience with Mr. Zarqawi’s strategy in Iraq and his attempt to stir up a civil war by killing Shiite civilians.

“I think the key question is, why did they release the video? Showing up on a video shows that he is in a good position and that he can deliver messages just like Osama bin Laden and Ayman al-Zawahri,” the director and co-founder of the SITE Institute, Rita Katz, said.

The SITE Institute, a Washington DC-based group that tracks extremist Web sites and conducts undercover research, first alerted Western news organizations yesterday to the prospect of a major announcement from the terrorists in Iraq. The institute has worked with the Department of Homeland Security, the Treasury Department and the FBI to provide timely information on terrorists.

Due to the numerous announcements on jihadi message boards, Ms. Katz said yesterday, “We were expecting something this morning.”

Seven hours later it appeared. She said she was surprised. “I was not expecting to see Zarqawi on a video.” Ms. Katz said. “This is the first time Zarqawi has ever appeared on video.”

While the gruesome video of a masked man beheading the American prisoner Nicholas Berg in May 2004 has long been suspected to be Mr. Zarqawi himself, analysts said yesterday’s video is certainly the first to feature an unmasked Mr. Zarqawi speaking directly to the camera – like a practiced actor.

One site where the video quickly appeared is known as “al-hesba,” a password-protected Web site that usually posts the latest statements from Mr. Zarqawi’s organization.

The coordination and distribution of Mr. Zarqawi’s first video was both complex and sophisticated. “We saw that it was immediately posted on four different sites with three to four dozen URL links offering the video for download all over the world,” Ms. Katz said.

Yesterday’s Zarqawi video calls into question analysis by the Washington Post, published a few weeks ago, that suggested the American military has exaggerated the importance of Mr. Zarqawi.

Many indications suggest the tape was made recently. On the tape, Mr. Zarqawi says it was recorded on “23 Rabi 1427,” which translates into April 21, 2006, in the Western calendar. Also, Mr. Zarqawi’s monologue refers to Secretary of State Rice’s visit to Iraq in early April and the three-year anniversary of the liberation of Iraq.

The video is “an attempt by Zarqawi to influence the public discourse and get out his misguided vision for misguided purposes,” Lieutenant Colonel David Farlow, a spokesman for Cent-Com, the central American military command responsible for operations in Iraq, said.

Until now, Mr. Zarqawi has only released audiotapes. His most recent audiotape appeared in January 2006. Audiotapes are believed to be safer for terrorists because they provide fewer clues to American and allied intelligence services about their whereabouts.

“Obviously we always hope that there will be some golden nuggets that will allow us to locate him and bring him to justice. It will be scrutinized by intelligence to see what we can glean from it,” Colonel Farlow said.

A spokesman for the U.S. Special Operations Command declined to comment on yesterday’s Zarqawi video.

However, through a technical analysis of the video tape the CIA has authenticated that it is indeed the voice of Mr. Zarqawi.

Perhaps the most surprising aspect of the video, aside from its unannounced release, is that is shows Mr. Zarqawi is a much heavier man than photos released a little over a year ago, following the capture of Mr. Zarqawi’s laptop computer.

The 38-year old terrorist appears to have been transformed into a beefy, middle-aged executive from a lean and hungry terrorist, with the kind of wolfish charm he used to seduce two wives.

Mr. Zarqawi’s apparent weight gain was immediately noticed by intelligence analysts, a CIA spokesman told the Sun.

Does that suggest that Mr. Zarqawi is not able to move around as much? “I wouldn’t read too much cosmic significance in the apparent weight gain,” a CIA spokesman said, who declined to give his name citing agency policy.

Appearing in his trademark skull cap, Mr. Zarqawi was dressed all in black, like a Spanish Civil War communist fighter. He is shown meeting with his inner circle, with a map on the floor and a gun leaning against the wall. He also shown marching along with a dozen or so masked fighters in a desert setting.

Some press outlets have speculated that the video was shot in Western al-Anbar province of Iraq. “No one in the building could say something so conclusive,” a CIA spokesman said, jokingly. “It could be Arizona.”

Mr. Zarqawi delivered a long monologue to camera, with a bandolier of ammunition around his neck. He appeared to be begging the Sunni insurgents not to join their co-religionists in Iraq’s new democratic government.

“God almighty has chosen you (Sunnis) to conduct holy war in your lands and has opened the doors of paradise to you … So mujahedeen, don’t dare close those doors,” he said. “They are slaughtering your children and shaming your women.”

He pointedly attacked Jawad al-Maliki, the new Iraqi premier, who said that the new unity government was drawn from Shiite, Sunni, and Kurdish parties.