The fraud and racketeering trial of Louisiana Gov. Edwin W. Edwards ended today with a jury unable to reach a verdict after a week of deliberations. In his inimitable, stage-grabbing fashion, Edwards reached the verdict himself.

"I've just won the 16th and most important election of my life," he said, "and by the greatest majority ever."

The jury foreman said the votes were 11 to 1 for acquittal on some of the 50 counts against him, 10 to 2 on others. U.S. District Court Judge Marcel Livaudais, who had twice urged the jury to break its impasse, finally declared a mistrial in the three-month, multimillion dollar proceedings.

"The prosecutor showed his side good," said one of the majority, 51-year-old Geneva Converse. "But the proof, the black and white, just wasn't there."

U.S. Attorney John Volz was visibly upset after Livaudais' decision. Earlier in the week, he had promised a retrial in the event of a hung jury, but today he said he was reassessing that position. In a harsh statement on the courthouse steps, Volz said the jury's refusal to convict Edwards and his four codefendants reinforced Louisiana's reputation as a place where political chicanery is tolerated if not encouraged.

"Apparently they were content with the type of activity that was shown to them," Volz said of the jurors.

Edwards, 58, appeared at a news conference two hours later, smiling broadly as his supporters and relatives gave him a standing ovation. Standing in front of a podium bearing the state seal, he declared the jury's indecision a complete vindication. He said he would remain in office and call a special session of the state legislature in January to deal with Louisiana's worsening economic conditions.

He also said that he would be a candidate for a fourth term as governor in 1987.

"On the day the indictment came down, when Mr. Volz was so confident of getting a conviction, I was innocent," Edwards said. "On the day the trial started, I was innocent. On the day the trial ends, I am innocent, and I will be innocent for the rest of my life, no matter what Mr. Volz says. After all of this, I simply want to say, 'How sweet it is!' "

Edwards, who was reelected two years ago with 63 percent of the vote, charged again that his indictment was a political vendetta by Democrat-turned-Republican Volz with support from Rep. Robert L. Livingston (R-La.), who may run against Edwards in the next gubernatorial race.

"Until somebody comes up with some basic, positive proof that I've done something wrong," Edwards said, "they should busy themselves catching bank robbers, interstate car thieves, drug smugglers and kidnapers . . . . "

Told that some people still assume that Edwards is guilty but that the prosecutors were not smart enough to catch him, the governor replied: "They've got it half right."

Edwards estimated that his defense, led by Nashville attorney James Neal, cost $50,000. Volz would not say how much the government's efforts cost, but sources estimated it at between $2 million and $3 million.

The essence of the case was this: In 1982, during the four-year hiatus between Edwards' second and third terms as governor, he formed a hidden partnership with codefendants James Wylie and Ronald Falgout. The prosecution alleged that the partners obtained profitable approval certificates for hospitals by bribing state officials with promises of promotions if Edwards returned to the governor's mansion.

The government contends that the enterprise continued when Edwards defeated incumbent Republican David C. Treen. His share of the profits was then allegedly transferred to his younger brother, Marion, who was acquitted earlier this week of 41 of 50 counts against him. As governor, Edwards issued a moratorium on hospital and nursing home projects, but exempted eight proposals, including two owned by his former partners.

Gov. Edwards acknowledged making about $2 million from the enterprise but denied that he had obtained it illegally.

Edwards was indicted in February and his trial began seven months later. Although the indictment listed 50 counts, Volz centered his case around bribery. "This case, in a nutshell, involves bribery," Volz told the jury, specifically the alleged bribery of John Landry, the official in charge of hospital certificates, and of Gov. Edwards.

Edward was the last witness, giving three days of testimony that was perhaps more entertaining than decisive. He regaled the courtroom with stories about his gambling adventures, and he relished the chance to spar with his nemesis, Volz. He portrayed himself as an intuitive leader, unconcerned with details, whose thirst for profit neatly coincided with hospital projects that would bring in needed jobs and provide Louisiana's people with more and better health care.

"I made some mistakes," Edwards testified. "But I give the people the best I've got."