(MENAFN - AFP) Wall Street raider Carl Icahn defended his twin attacks on computer giant Dell and offshore oil rig operator Transocean, saying such companies need "shaking up" for shareholders' benefit.A day after singling out the two companies for his legendary brand of investor activism, the Wall Street buccaneer told AFP that he is doing what he has always done: pressing companies and chief executives to perform better and reward investors better."What we do by shaking up a large number of companies that need shaking up is very salutary for our economy," Icahn said in an exclusive telephone interview on Friday."Many of our companies, but with many exceptions, are run by CEOs that should not be running them," Icahn said. "And as a result, these corporations are not as productive as they should be."On Thursday, Icahn joined another key Dell shareholder to resist founder Michael Dell's attempt to take it private for what the dissidents call a deep discount to the company's true value.Icahn threatened "years of litigation" as he proposed an alternative to Dell's 24.4 billion offer: instead of going private, the company should make a special 9 a share dividend payment.Even after that, Icahn said, the company will still be worth more than the 13.65 that Dell's investor group is offering.Separately, he attacked Transocean's management to force a higher dividend payout, lambasting them for a "failed strategy."Icahn, who ranks 26th on the Forbes list of billionaires with a net worth put at 20 billion, has also plunged into the rival hedge fund battle over nutrition product marketer Herbalife.At age 77 and after dozens of some of the roughest proxy battles in modern corporate history, Icahn shows no sign of slowing down.In cases ranging from TWA to RJR Nabisco and Blockbuster Video, the street-fighter has pushed, prodded and poked his way to great wealth.He is from the same generation as famed investor Warren Buffett.But unlike Buffett, a long-term, relatively passive investor, Icahn makes his money by taking positions in companies that give him the leverage to force changes in management or rewards to shareholders, or both."Icahn is part of a long tradition on Wall Street of the skilled activist -- sharp, insightful, goes for the jugular, motivated by results and not popularity," said Marshall Sonenshine, chairman of Sonenshine Partners."What is unique about him in this business is his not his bluntness, but his age."Icahn stopped working for investors in 2011 and decided to use only his own money.His tactics still inspire fear and awe on Wall Street."People respect his opinion," said Chris Low, chief economist of FTN Financial. "I know on our trading floor, when we see him on television, we tend to turn up the volume and pay attention."His wily moves have built him a fortune.In 1987, Icahn pressured oil giant Texaco to settle a lawsuit with Pennzoil over the acquisition of Getty Oil, after a Texas court ordered Texaco to pay 10.5 billion.The settlement netted him a payoff of some 600 million, according to press accounts.In 1996-97, Icahn moved on to RJR Nabisco in an effort to force it to split its tobacco business from the food division to boost the overall value for shareholders.He failed, but still came out smiling after selling his shares at an estimated gain of some 100 million.One Wall Street analyst described the deal as someone "who came to the party, took 100 million from the bar, and left," according to The New York Times.Icahn's current campaigns show he isn't retreating one bit from the rough-and-tumble of Wall Street.With Transocean, Icahn is pushing for a 4 dividend for shares and the election of three new directors.His plan, he wrote, constitutes "the only way that Transocean will consistently employ a disciplined and sensible approach to capital allocation."With Herbalife, he has taken the side of one hedge fund titan, Daniel Loeb, against another, Bill Ackman, who has shorted the company."We've done a lot of research," Icahn said. "We obviously think the stock is cheap and we think Ackman is wrong."With Dell, Icahn insists that he thinks the future of the company "is bright".But, he wrote in a letter to the company's board, "we see no reason that the future value of Dell should not accrue to ALL the existing Dell shareholders -- not just Michael Dell."As always, he could just settle for a higher price. Jefferies analyst Peter Misek said he sees dissidents could agree to the buyout at 15 a share."We also think Icahn could be satisfied with a raised bid," Misek said.