NEW YORK (CNN/Money) -- Prosecutors indicted ex-Tyco International CEO Dennis Kozlowski, former CFO Mark Swartz and ex-general counsel Mark Belnick Thursday on charges of orchestrating a web of deals that looted the company of at least $600 million.

The three men were led into court in handcuffs and later pleaded not guilty in New York State Supreme Court. Kozlowski was released on $100 million bail while Swartz's bail was set at $50 million.

The assets of both men, about $600 million, were frozen by a restraining order obtained by the state. Belnick was released on a $1 million bond.

The pleas came hours after Manhattan District Attorney Robert Morgenthau announced the indictments, charging Kozlowski and Swartz with stealing $170 million in company loans and other funds, as well as obtaining more than $430 million through fraudulent sales of securities.

Tyco is one of several large corporations whose books are being scrutinized by prosecutors and federal regulators, Enron Corp., WorldCom Inc. and Adelphia Communications also among them. The latter three firms have filed for Chapter 11 bankruptcy protection from creditors.

Investigation began in January

Prosecutors began investigating Tyco in January on a tip from banking sources about a fuzzy transaction at the company, Morgenthau said at a news conference. The probe led investigators to Kozlowski's art purchases, and then the other expenditures. He was indicted in June on charges of scheming to evade taxes on the paintings.

The Securities and Exchange Commission filed a separate but related civil lawsuit charging that the three men failed to disclose multimillion-dollar low-interest and interest-free loans they took from the company, and in some cases never repaid. The SEC also said the three former executives failed to disclose their personal sales of millions of dollars' worth of Tyco stock.

"Kozlowski, Swartz and Belnick treated Tyco as their private bank, taking out hundreds of millions of dollars of loans and compensation without ever telling investors," Stephen Cutler, the SEC's director of enforcement, said in a statement announcing the action. "Defendants put their own interests above those of Tyco's shareholders. Those shareholders deserved better than to be betrayed by the management of the company they owned."

Lawyers for the three men could not immediately be reached for further comment Thursday.

Kozlowski and Swartz were charged with corruption, conspiracy, grand larceny and falsifying records. The two men each face up to 30 years in prison if found guilty of all the charges. Belnick, charged with falsifying business records, faces up to four years in prison.

Tyco also said it sued Kozlowski, seeking to get back pay and benefits since 1997 of about $244 million, as well as the forfeiture of all his severance pay. The company, a maker of crutches, undersea cable and other products, previously had sued Belnick in a bid to recover millions of dollars it claims he misappropriated.

Accused of misappropriating millions

Thursday's indictment accuses Kozlowski of spearheading a plan, with the help of Swartz and Belnick, to misappropriate millions of dollars of company money for himself and his colleagues through unapproved and undisclosed payments and loans.

The new charges follow a 14-count indictment against Kozlowski on charges of evading sales tax on expensive works of art, including works by Renoir and Monet. Kozlowski, who resigned from Tyco in June a day before being indicted, pleaded innocent to those charges.

According to Thursday's indictment, the men manipulated two corporate loan programs in order to obtain funds to buy homes and artwork, and to give themselves unauthorized bonuses. Kozlowski and Swartz later caused many of the loans to be forgiven, the charges said.

Kozlowski borrowed $9 million to buy property in Boca Raton, Fla., in 1998 as well as $7 million to buy a Park Avenue apartment in Manhattan for his wife as part of a divorce settlement, according to the indictment. Additionally, Kozlowski is charged with giving himself a $56 million bonus and Swartz a $28 million bonus, neither of which was disclosed to the board of directors.

In addition to the homes in Florida and New York, the men used millions in company money to buy homes in Nantucket, Mass., and Rye, N.H., as well as to buy yachts and pay for home renovations and jewelry from Tiffany and Harry Winston, and other items.

The indictment also charges the men with stealing $20 million by giving it to a Tyco director without informing the board or obtaining approval. Kozlowski is charged with stealing $2 million and 200,000 shares of stock by giving Belnick an unauthorized bonus, prosecutors said.

False loans alleged

Aside from extravagant purchases, prosecutors say Kozlowski and Swartz bilked investors out of more than $400 million by falsifying and manipulating information in proxy statements and other documents, and in meetings with investors, analysts and reporters. They allegedly hid the fact that they received tens of million of dollars in forgiven loans and payments, and routinely filed documents falsely stating they had no outstanding debt in excess of $60,000.

Kozlowski also told investors he had faith in Tyco while not fully disclosing his own sale of 5.5 million Tyco shares that yielded him $280 million, the indictment charged. Swartz, meanwhile, sold more than 2 million shares of Tyco, handing him more than $125 million.

Meanwhile, Tyco is trying to overhaul its management and board of directors. On Thursday, the company named former International Paper executive William Lytton as executive vice president and general counsel, replacing Irving Gutin, who had filled the job after Belnick left Tyco in June. Lytton is a former federal prosecutor who served in Chicago and Philadelphia.

His appointment comes a day after Tyco named David FitzPatrick as finance chief to replace Swartz, who resigned last month. FitzPatrick has held jobs at numerous blue-chip firms. Last month, Tyco tapped former Motorola executive Edward Breen to replace Kozlowski.

Meanwhile, Tyco's board Thursday agreed to boot nine board members, and nominated five people to fill the vacancies as it continues to clean house.

Tyco's shares ended unchanged in U.S. trade on Thursday but are well below their 52-week high of $60.09. J.P. Morgan raised its rating on Tyco to "buy" from "long-term buy" Thursday, saying its corporate reform efforts are moving at a "dazzling pace."