Shamrock boosted its stake in an ad agency.

The Burbank investment concern owned by the Roy E. Disney family said it increased its stake in Foote, Cone & Belding Communications to 9.9% from 7.4% in early March. Shamrock Holdings also said it has received federal approval to proceed with its previously announced plan to acquire up to 25% of the Chicago-based agency. Shamrock added that it may seek to influence FC&B; policies and request seats on its board.