PORTLAND – Maine’s largest daily newspaper will cut more employees to make up for an advertising revenue shortfall in what will be the paper’s fourth round of layoffs in the past year.

The Portland Press Herald reported Friday that ad revenues have declined at a faster rate than projected at the time of the last round of cuts, when the paper cut 36 jobs and closed its four news bureaus.

Publisher Charles Cochrane said second-half ad revenues are now expected to be about $1.2 million less than what was forecast in May. To meet commitments to debt holders, Cochrane said the company has to reduce operating expenses by a comparable amount.

The Press Herald and its sister papers in Augusta and Waterville are all up for sale by the Seattle Times Co., which has owned the newspaper group for the past decade.