The bus was on its way to the Caylabne Resort and was negotiating a winding, downhill road when the accident occurred at about 8:45 a.m., police said.
The Unilever employees were to attend a seminar at the resort.
Police said the brakes of the rented bus, driven by Ismael Aguda of Warner Transport, could have malfunctioned, sending the bus heading toward the cliff, plowing through the concrete barricade and plunging into the 20- to 30-foot deep ravine.
The four fatalities were identified as Eduardo Noveloso, 46, of Novaliches, Quezon City; Dominador Medina, 50, of San Pedro, Laguna; Raymond Honorio and Romulo Paragas.
They were pronounced dead on arrival at the Cavite Medical Hospital in Maragondon town.
Besides Aguda who sustained cuts and bruises, injured were Jojo Alinio, Maria Paz DeCuy-cuy, Amday Chome, Mercado Risaros, Zeny Dimaterio, Arturo Yee, George Enrique, Robert Miel, Henry Terana, Marcelino Soliman, Marcelino Gangdelino, Lauro Sunchuangco, Jet Derandino, Eric Mercado and Dionisio Fajardo, the bus conductor.
Marine soldiers stationed in Barangay Calumpang here and members of the Philippine National Red Cross assisted in the rescue.
Unilever said its plant in Manila will be shut down until today as company officials work overtime to airlift the injured and the fatalities. — With Jaime Laude, AFP