Silicon Valley-based networking equipment maker Juniper Networks Inc. said Wednesday it expects to take a $900 million charge after an investigation found “numerous instances” of backdated stock options grants that were not properly recorded in the company’s books.

Nearly all the expense relates to problems with options granted between June 9, 1999, and Dec. 31, 2003, the company said in a statement. Juniper earned a total of just $45 million from 1999 through 2003 — a figure that will be obliterated by the company’s anticipated charges to correct its misleading accounting for those years.