PLANS TO RENOVATE THE LOUVRE MUSEUM IN PARIS have been delayed owing to Finance Minister Edouard Balladur's refusal to move his offices. The decision means the project designed by I.M. Pei will not be completed until the end of the century. It will not affect the erection of a tall glass pyramid marking the museum's main entrance, which is to be inaugurated next spring. THE SAN FRANCISCO-BASED KRONOS QUARTET will appear in Becket, Mass., on Sunday afternoon at the Jacob's Pillow Dance Festival. The string quartet will perform works by Kevin Volans, Ge Gan Ru of China, Terry Riley, and Alfred Schnittke of the Soviet Union. LEADERSHIP AT THE KENNEDY CENTER FOR THE PERFORMING ARTS will change as Ralph P. Davidson becomes its president. He replaces Roger L. Stevens, who was named by President Kennedy to establish the arts institution. Mr. Davidson is to retire next year from Time Inc., where he is chairman of the executive committee.