"Pfizer has created and contributed to the perception of Viagra as a safe, sexy, lifestyle, recreational drug, to be frequently used regardless of the degree, or even existence of" erectile dysfunction, the group said in draft legal documents.

Pfizer, the world's largest drug maker, said it was committed to appropriate Viagra use and urged men to see a doctor for a proper diagnosis. The drug is sold by prescription.

The AIDS Healthcare Foundation, in its legal arguments, pointed to several Viagra promotions from recent years, including a 2005 newspaper ad that featured a smiling man asking, "What are you doing on New Year's Eve?"

Another ad that ran near the 2006 Super Bowl urged men to "Be this Sunday's MVP" and ask their doctors about Viagra.

Pfizer's Viagra website asks readers, "Want to improve your sex life?" and says the drug can help men who have erection difficulties "once in a while."

Healthcare foundation president Michael Weinstein said the promotions made Viagra sound like a "party drug" that can make sex more pleasurable for healthy men -- a claim the Food and Drug Administration has not approved.

Men in the ads also look much younger than Pfizer's earlier Viagra pitchman, former Kansas Senator Bob Dole, who is now 83, he said.

"Bob Dole has been replaced by the hunky 40-something guy who looks like he can really have a good time," Weinstein said in an interview. "The message they are sending out is that any and every male should take it," he said.

Studies show evidence of recreational Viagra use among men who have sex with men, sometimes to overcome the erection-inhibiting effects of alcohol or street drugs such as ecstasy and crystal methamphetamine, the AIDS Healthcare Foundation said.

The group asked Pfizer repeatedly to alter its ads, Weinstein said.

In 2004, the FDA objected to a television commercial suggesting Viagra could return a man to the "wild thing" of his younger days. The FDA said the ad, showing a man sprouting devilish horns, made an unproven claim that men could regain a youthful level of sexual desire. Pfizer halted that campaign.

The AIDS Healthcare Foundation's lawsuit, to be filed in Los Angeles Superior Court, asks that Pfizer be prohibited from running similar messages and ordered to fund awareness ads about sexually transmitted disease risks and Viagra.

The suit also requests that Pfizer turn over profits gained from misleading ads and pay the AIDS Healthcare Foundation's costs of treating AIDS and other illnesses linked to Viagra use.

California-based AIDS Healthcare Foundation runs AIDS clinics in the United States, Africa, Latin America, the Caribbean, and Asia that provide medical care and services to more than 53,000 people even if they cannot pay.

Pfizer spokeswoman Shreya Prudlo said the company was not aware of the lawsuit. She said Pfizer "has always been committed to safe and appropriate use of Viagra" and that the drug's label and promotions stated "Viagra does not protect against sexually transmitted diseases, including HIV."

Sales of Viagra, known generically as sildenafil, reached $1.6 billion worldwide in 2005.

Christopher J. Steskal, a lead prosecutor of a federal task force investigating the backdating of stock options at Apple Inc. and other companies, is leaving his San Francisco post to join a law firm, the United State Attorney’s office in San Francisco confirmed late Friday.

Mr. Steskal’s decision follows the recent resignation of his boss, United States Attorney Kevin V. Ryan.

Mr. Steskal also was the lead prosecutor in the government’s case against Gregory L. Reyes, the former chief executive of Brocade Communications Systems.

Mr. Steskal, who was to try Mr. Reyes’s case in June in San Francisco, is the second of five assistant United States attorneys on the task force to leave since its formation in July. He said he would join the San Francisco office of Fenwick & West within 30 days.

William J. Portanova, a criminal defense attorney and former federal prosecutor, said that he believed that the Brocade case would not suffer, no matter who is picked to succeed Mr. Steskal.

“The government has people stacked up ready to pick up the case and run with it,” he said.

Luke Macaulay, a spokesman for the United States Attorney’s office in San Francisco, said that one of two prosecutors the office is planning to hire would replace Mr. Steskal on the task force.

An Iraqi cabinet-level committee proposed a draft law Friday that would allow the national government in Iraq to control oil revenues. Negotiations concerning the draft law have been a source of tension in Iraq for months as most Kurds and many Shiites want to retain control of the country's oil resources. On the other hand, Sunni Arabs, who do not dominate the oil-rich regions of the country, insist on central oversight.

Recent debate has centered on the establishment of a federal committee, called the Federal Oil and Gas Council, to review oil contracts. Kurds did not want to give the committee the power to "approve" contracts, so the draft law instead allows regions to initiate and guide the process of awarding oil contracts and gives the committee the power to review and reject contracts. The Iraqi cabinet and the country's parliament must approve the draft before it becomes law. If the draft passes, enforcement might prove difficult in Iraq's wartime environment.

Mexico extradited drug kingpins Osiel Cardenas and Hector "El Guero" Palma and thirteen other major traffickers to the United States Friday as part of an effort by new Mexican president Felipe Calderon to follow through on a promise made by former President Vincente Fox to make increased extraditions to the US. Since taking office, Calderon has mobilized elite police and military forces against the rival Sinaloa and Gulf Cartels. Although the widely popular initiative is showing initial success, experts warn that Calderon must address the political and judicial corruption that allows cartels to run rampant in Mexico.

Kingpins are often able to continue running their organizations from within corrupt Mexican prisons, making the extradition of leaders a key tool for scaling back cartel activity. In November 2005, the Supreme Court of Mexico ruled that prisoners serving life sentences can be extradited abroad, overturning a 2001 decision that prevented such prisoners from answering to charges in the US insofar as punishment there might be cruel and unusual and not directed at rehabilitation of the prisoner. A 1978 treaty between the US and Mexico still prevents the extradition of prisoners who face the death penalty.

Vioxx manufacturer Merck Pharmaceuticals, which withdrew the drug from the market in 2004 after research showed it doubled the risk of heart attacks and strokes, claimed that the men's heart problems were caused by pre-existing coronary heart disease, and not the drug. After the mistrial was declared, Merck announced that the plaintiffs did not prove their cases, and that they were ready to defend against the allegations if they were brought fourth again. As of the end of last November, Merck faced 27,200 lawsuits over Vioxx and another 265 potential state-based class-action lawsuits. A federal judge rejected national class-action lawsuits in federal court early in November.

Issue ads are those that do not purport to influence an election, but rather focus attention on an issue their sponsors find important. A provision of the McCain-Feingold law prohibits mentioning a candidate in issue ads in the 60 days before a general election and 30 days before a primary.

Its purpose was to end the common practice of circumventing limits on contributions in federal elections by airing ads that avoided expressly advocating a vote for or against someone while making clear a preference for, or more often, disapproval of one candidate.