Next Media is offering HK$1 million to track down the assailants and mastermind behind a recent series of attacks believed to be targeted at the news group.
Group chairman Jimmy Lai Chee-ying yesterday said he and his group would not be scared off by such "childish acts".
The latest attack - the fourth in 13 days - came just hours after a machete was found outside the entrance to the Next Media building in Tseung Kwan O.
At about 12.30am yesterday, three armed masked men burned about 26,000 copies of yesterday's issue of the Chinese-language Apple Daily in Central.
The men pointed a knife at two workers in Edinburgh Place and poured flammable liquid on the newspapers before torching them, police said.
Next Media condemned the attacks. "[We are] offering a reward of HK$1 million to anyone who can provide information or clues that could lead directly to the detection of the cases," it said.
Lai, who had morning tea with his Democrat friends in Central yesterday, said he was not worried.
"It's good thing. It will drive more people to take to the streets," he said, referring to today's planned democracy march.
"There's no need to worry. It's only a childish act. This will not affect [my newspaper's editorial policy]," he added.
Lai, whose news group has been highly critical of the post-handover Hong Kong government, is known for his anti-communist stance.
The series of attacks started on June 19, when a stolen car was rammed into the front gate of Lai's Ho Man Tin house, and an axe and a machete were left in his driveway.
A week later, two masked men intercepted a delivery van in Hung Hom and torched bundles of the Apple Daily on board before fleeing.
The Journalists Association condemned the attacks and urged the police to arrest the assailants as soon as possible.