HONG KONG — Hong Kong's billionaire Kwok brothers pleaded not guilty to graft charges Friday, setting the stage for the city's biggest corruption trial in years. The pleas entered by Thomas and Raymond Kwok all but ensure their case will head to trial in the city's High Court. The brothers are joint chairmen of Sun Hung Kai Properties Ltd., one of Hong Kong's biggest developers. Forbes estimates they are the third richest people in Hong Kong, with a combined net worth of $20 billion. Anti-corruption police arrested and charged the Kwoks last year, along with three others. Prosecutors had alleged that the prominent developers gave bribes in exchange for lucrative information on pending land sales. But they slightly revised the charges, dropping the bribery charge against Raymond Kwok. The brothers still face charges of misconduct and providing false information. The three other defendants also pleaded not guilty. They include Rafael Hui, formerly the second highest ranking government official; a former senior officer at stock exchange operator Hong Kong Exchanges and Clearing; and an executive director at Sun Hung Kai. Hui is alleged to have provided land sale information to the Kwoks between 2005 and 2007. The corruption scandal shocked the southern Chinese financial center, where residents have traditionally revered the city's tycoons. But widening inequality, much of it linked to skyrocketing housing costs in the densely populated city, means that has given way in recent years to public anger over the billionaire class, many of whom made their fortunes in property. Prosecutor Kevin Zervos said at the brief hearing that 72 witnesses would testify. Their not guilty plea was entered after the prosecution dropped one of the three charges against the younger brother, Raymond, which alleged he conspired to offer an advantage to Hui. Speaking in Cantonese alongside two other accused, all five told magistrates that they pleaded not guilty. The court then agreed to shift the trial to the high court. “You are now committed to the Court of First Instance for trial,” Magistrate Li Kwok-wai said, before he adjourned the hearing. It is a case that has gripped Hong Kong as the Kwoks own some of its most iconic real estate — Sun Hung Kai is the city's biggest property developer, based on market capitalisation. The Kwoks have an estimated family wealth of US$20 billion, according to Forbes magazine. Analysts said the case reinforced public suspicion that officials were in the pockets of Beijing-backed business elites, who control everything from ports to telecommunications and even supermarkets in Hong Kong. — Agencies