Di Turns 26 by Herself; Charles at Job Center

LONDON — Princess Diana marked her 26th birthday today with a visit to the Wimbledon tennis tournament as press speculation grows bolder that her marriage to Prince Charles is in trouble.

At 38, Charles’s interests and life style often are at odds with those of his wife.

Diana, for example, spent this afternoon in the royal box at Wimbledon’s Centre Court, watching a match between Ivan Lendl and Henri Leconte. Fans broke out in a spontaneous chorus of “Happy Birthday” upon realizing she was there.

Charles, who is involved in projects to redevelop Britain’s inner cities, toured a job center in London’s run-down East End.

Buckingham Palace released no details on any plans for a celebration of Diana’s birthday.

Romantic Rumors

In recent weeks, some tabloids have hinted Diana is romantically involved with banker Philip Dunne, a dancing partner at parties she has attended alone or stayed at long after Charles had gone home to bed.

But a story in today’s 4 million-circulation Sun was the first to go so far as to speculate on the mechanics of a royal divorce.

“Just imagine if . . . Charles and Di did the unthinkable and got divorced?” the newspaper said in a front-page headline.

“What would happen to Charles? Could he still be king? Would he ever marry again? What would Di do? Where would she live? Would she ever be allowed to see her kids?”

“Picture the scene,” the newspaper said. “Senior royal advisers gather at Buckingham Palace for the saddest task of their lives . . . to thrash out the details of an historic announcement that will stun the world: The magic marriage is over.

“Unthinkable, yes, but the unthinkable keeps happening to the Royal Family.”