HONG KONG -- The Asian gambling mecca of Macau is bracing for the release on Saturday of a notorious organized crime boss who was at the centre of the gangland violence that plagued the city in the late 1990s.

Wan Kuok-koi, also known as "Broken Tooth Koi," is scheduled to walk free from Coloane Prison sometime between midnight Friday and noon Saturday after serving most of a 15-year sentence, the Macau government said.

Wan was convicted of loan sharking, money laundering and being a gang leader in November 1999, a month before Portugal handed control of Macau, its colony for more than four centuries, back to Beijing. As head of Macau's 14K triad, Wan waged a brutal war with rival triads, or organized crime gangs, for dominance of the lucrative VIP rooms in Macau's casinos.

Wan was arrested shortly after a bomb destroyed the car of Macau's director of investigative police, Antonio Marques Baptista, who was out jogging when the vehicle exploded and unscathed by the assassination attempt.

According to news reports in Macau and nearby Hong Kong, authorities have been preparing for his release by warning hotels and casinos to tighten security and plan to keep a close eye on him after he gets out. Officials, including one from Beijing's liaison office with Macau, have also warned Wan to behave after his release, the reports said.

The measures are a response to fears that Wan's release would be followed by a return to the pre-handover gang violence that rocked Macau and claimed dozens of lives, including 37 in 1999 alone. Some worry he'll try to get involved again with junkets, which arrange for wealthy mainly Chinese gamblers to come to Macau, lend them money and make big profits by collecting on debts.

But analysts say that when Wan leaves prison, he'll likely find he has lost much of his power and influence following Macau's decade-long transformation from a seedy and corrupt crime-ridden backwater into the world's top gambling market.

Macau's decision to end a four-decade casino monopoly in 2002 opened the way for foreign operators to modernize the industry. Las Vegas Sands Corp., MGM Resorts International and Wynn Resorts Ltd. have all opened glitzy resorts in recent years. Macau is the only place in China where gambling is legal.

"Wan Kuok-koi is yesterday's man," said Steve Vickers, a former head of intelligence at Hong Kong's police force who is now chief executive of business intelligence and risk consultancy SVA.

"Whilst he remains connected with his previous gang members, there is just no room for the wild bunch in Macau anymore. He will be neutralized should he create trouble," said Vickers, who noted that while Wan has been in prison, Macau's gambling revenues have rocketed from US$2.5 billion in 2002 to $33.5 billion last year, more than five times the amount earned on the Las Vegas Strip.

In his heyday, Wan was a larger-than-life figure who seemed to have come straight out of a movie. In fact, he commissioned a film based on his life that was released in 1998. To shoot a key scene in "Casino," a shoot-em-up gangster flick, the crew blocked off a major bridge despite being denied permission by officials, who were left fuming. The Hong Kong Standard newspaper said Wan was also known as Broken Tooth Koi because in his youth he cracked a tooth in a car crash but later had it capped.

When Wan gets out of prison, he'll find a Macau that he'll scarcely recognize. To accommodate flashy, oversized Las Vegas-style casinos, city planners filled in a stretch of swampland between two islands in the land-scarce enclave. The new Cotai district is home to the Venetian Macao, the world's biggest casino, and similar resorts in a sharp contrast to the aging Hotel Lisboa in the cramped city centre where Wan was arrested.

Tourists, who once stayed away because of the violence, now flood in to the city of just over half a million. Some 28 million, most of them from mainland China, arrived in the year to September.

Violence abated after Wan went to prison and Macau has been largely peaceful until a spate of violent incidents this year that included the beating of a junket operator in his own casino and the killings of two mainland Chinese men and, separately, the death of a mainland Chinese woman. The killings remain unsolved. Following the violence, Macau police questioned 1,300 people and arrested 150 in raids at casinos and hotels across the city.

Macau watchers doubt there will be a return to further violence. They note that while Wan was in prison, the junket industry has cleaned up its act and become more professional. There's much more money at stake now and few want to jeopardize that.

"I just don't see these guys having the same sort of appetite for violence as they had in the past," said Aaron Fischer, a gambling analyst at CLSA Asia Pacific Markets. "In simple terms I think a lot of these guys have grown up."

Beijing is also anxious to maintain law and order in Macau, said Grant Govertsen, a Macau-based analyst at Union Gaming Group.

The measures taken by authorities ahead of Wan's release, Govertsen said, are "likely part of an effort to emphasize China's priority to keep Macau safe and prosperous."