Yahoo Inc plans to lay off more than 600 employees as early as Tuesday, two sources familiar with the situation said on Monday.

The cuts would represent between 4 percent and 5 percent of the Internet portal's overall staff, which totaled 14,100 at the end of September according to Yahoo's website.

The layoffs come two years into Chief Executive Carol Bartz's tenure as Yahoo works to grow its revenue amid tough competition from Google Inc and Facebook.

Yahoo declined to comment.

Technology blog AllThingsD wrote earlier this month that Yahoo planned to cut 650 employees, and the New York Times newspaper reported on Monday that the cuts could take place as soon as Tuesday.

A source familiar with the situation said the New York Times report was accurate and that the cuts would mostly be in Yahoo's product group. Another source told Reuters that Yahoo planned to cut between 600 and 700 employees from the product group on Tuesday.

(Reporting by Alexei Oreskovic; Editing by Richard Chang)