Citadel said bylaw changes may derail its merger.

The Glendale-based savings and loan holding company said corporate bylaw changes sought by a group of dissident shareholders could derail the planned merger of the firm with Great Western Financial. Citadel, parent of Fidelity Federal Savings & Loan, urged shareholders to reject proposals put forth in a proxy solicitation from a group led by Los Angeles investor Alfred Roven. In May, Great Western offered to acquire Citadel in a deal valued at $109 million.