GWANGJU, South Korea -- The chief of the operator of the sunken South Korean ferry and four employees are to appear in court Friday to enter pleas on charges that their negligence caused the April disaster that left more than 300 people dead or missing.

Kim Han-sik, 73, CEO of Chonghaejin Marine Co., and four executives or managers at the operator were set to enter pleas during a preliminary hearing at Gwangju District Court.

Prosecutors indicted them for alleged professional negligence and violating a law on measures required for safe maritime navigation.

Chonghaejin is said to have continued to overload the ferry Sewol with cargo even though the company knew the ship's redesign made it top heavy and unstable. By routinely overloading the Sewol with cargo, Chonghaejin made an extra $3 million in profit in the past year, according to indictment.

The Sewol sinking has caused widespread grief and fury here and has prompted South Korea to reassess its long history of disregarding safety as it pursued inclusion in the ranks of advanced countries. President Park Geun-hye has publicly apologized and reshuffled her Cabinet.

Last week, all but one of 15 crew members responsible for navigating the ferry pleaded not guilty to charges linked to their alleged failure to protect passengers, who were mostly high school students on a school trip.

The crew members, including the captain, said through their lawyers that their employer was responsible for the ship's sinking because sailors had no control over cargo. They said the coast guard was responsible for rescuing passengers.

The Sewol, a 6,825-ton car ferry purchased in Japan for 800 million yen ($7.8 million) in 2012, was redesigned to add cabins and create an exhibition room after its purchase, according to the indictment. The ship became top heavy as a result of the rework, so the Korean Register of Shipping approved the ship on the condition that it substantially reduce its cargo limit. An inspector at the Korean Register of Shipping has been charged by prosecutors.

Prosecutors and police officials are still seeking to arrest Yoo Byung-eun, a fugitive billionaire businessman who founded the predecessors of Chonghaejin. The government is offering a $500,000 reward for tips about his whereabouts.

Yoo faces allegations of tax evasion, embezzlement and professional negligence. Officials suspect the sinking may have happened because Chonghaejin illicitly funneled profits to his family and failed to spend enough money on safety and personnel.

In April, Yoo denied his involvement in day-to-day operations of Chonghaejin through a statement released by his representative. Authorities are offering $100,000 for clues about his eldest son's whereabouts, and one of his daughters was arrested in France late last month.

Meanwhile, 292 bodies have been recovered and 12 people are still missing from the ferry sinking, one of the most deadly peacetime disasters in South Korea.