Nelson Nadura, 42, had just left radio station dyME on his motorcycle when two gunmen, apparently waiting along the road, shot him from afar, provincial police chief Romeo Mapalo said.
Nadura fell from his blue Yamaha motorcycle, and the gunmen moved closer and fired more shots then fled toward a wooded area, he said.
Seven caliber .45 shells were found at the scene, and Nadura died from multiple gunshot wounds in the chest, Mapalo said.
He said police were interviewing witnesses and were working on a sketch of the assailants.
Nadura was the Masbate chief of the New Peoples Army (NPA) until he availed himself of the governments amnesty program in 1998, Mapalo said.
In his morning broadcast before he was killed, Nadura had criticized local officials involved in an unfinished highway project where traffic often builds up. It was along that road where he was shot.
Nadura had been hosting his morning program on dzME, owned by the Espinosa clan, for the past three years.
"If he did not work as a radio commentator, he would still be alive today," Naduras wife Vilma said.
The Masbate chapter of the Union of Broadcasters and Print Journalists, of which Nadura was president, condemned the killing, saying it was an attempt to stifle the freedom of the press as the societys watchdog.
Nadura was the second mediaman slain in Bicol this year. John Villanueva Jr., a broadcaster of dzGB here and a former vice mayor of Camalig, Albay, was shot dead in front of his house last April 29. The killing remains unsolved.
Despite its freewheeling press, the Philippines is considered one of the worlds most dangerous places for journalists.
At least 42 reporters have been killed since 1986, including six this year, according to the Center for Media Freedom and Responsibility, a media watchdog. Seventeen journalists have been slain over the past five years.
Last month, President Arroyo offered a P1-million reward to help solve the killings. With wire reports