The union says many journalists employed by the group earn less than £15,000 a year, with some on statutory minimum wages.
Nicola Coleman NUJ Irish organiser said: “For years this company has driven down wages and pocketed the money it saved. It is inconceivable that an employer can be left unchallenged when it pays wages from the last century.
“This strike is to ensure that once again journalists in these newspapers have a union agreement that delivers fairness in pay, fairness in working hours and fairness in all aspects of their working life.
“NUJ membership across the group has rocketed in recent months and more than 85 per cent of the journalists employed in these titles are set to strike. They are determined to take a stand for fairness and respect.
“Journalists’ wages have not kept up with inflation and a 14.5pc pay rise is required to deal with this issue alone. All we are asking for is basic decency and respect and we are asking the employer to voluntarily choose to accept these principals.”
Alpha has previously stated the pay increase being demanded by the NUJ is “totally unrealistic in the current environment”, adding the group is “committed” to improving the overal remuneration of all staff.
The strike will take place on Thursday, Friday and Monday, although journalists at the Ballymena Guardian will only walk out on the first day of action.