* Talks to resume at 5 p.m.

* Sticking points include lifetime job guarantees

* Newspaper Guild is final holdout in negotiations

By Jason Szep

BOSTON, May 5 (Reuters) - The Boston Globe's biggest union will resume contract-concession talks on Tuesday evening with the paper's owner, the New York Times Co (NYT.N: Quote, Profile, Research), which has threatened to shut the money-losing broadsheet.

The Times Co, which bought the Globe for $1.1 billion in 1993, threatened in early April to close the 137-year-old newspaper unless its unions agree to $20 million of concessions to staunch $85 million of projected losses this year.

Six of the seven unions representing employees of the Globe have now reached tentative agreements. Talks with the lone hold-out, the Boston Newspaper Guild, are scheduled to resume at 5 p.m., said Globe spokesman Robert Powers.

The future of New England's largest newspaper has been in doubt during a month of negotiations that have stumbled over the contentious issue of lifetime job guarantees enjoyed by about 190 members of the Guild.

The Guild, representing some 600 workers including the newsroom staff, has sought to preserve lifetime job guarantees, saying their elimination would pave the way for layoffs of some of the paper's highest-paid veteran staff.