JENNIFER ANISTON and ANGELINA JOLIE have made a lunch date to bury the hatchet once and for all — and friends are hoping it won't be in each other's back!

The longtime archenemies vowed to put aside their differences after Jennifer, 43, sent flowers to Angie, 36, congratulating her on her engagement to Jen's ex-husband BRAD PITT, The ENQUIRER has learned exclusively.

The gesture prompted Angie to call Jennifer to thank her, which led to an invitation to lunch in London late this summer. Jennifer will be in England getting ready to film a new movie, "Miss You Already," while Angelina is working on two projects overseas.

But pals fear there's too much bad blood between the women — and that their luncheon may turn into the cat fight of the century!

"Jen and Angelina have hated each other for years, and they've each thought long and hard about what they'd say if they ever got face to face," said a friend of Jennifer.

"Angelina will be going on the attack about Jen always playing the victim — and Jen is going to blast back at Angie for being Hollywood's greatest husband stealer."

Pick up The ENQUIRER — on newsstands now — for all the details!