Ashton-Tate Corp. said it has signed an...

Ashton-Tate Corp. said it has signed an agreement with Interbase Software Corp. of Tyngsborough, Mass., to jointly develop portions of Ashton-Tate’s next generation of database management software. As part of the agreement, Ashton-Tate, best known for its dBase software programs for personal computers, has purchased a undisclosed stake in Interbase for an undisclosed sum.