McDonald's french fries are now trans-fat-free in all its restaurants in the United States and Canada, the fast-food restaurant chain said Thursday.

McDonald's has lagged other restaurant operators in switching over to a zero-trans-fat cooking oil out of worries it would compromise the taste of its trademark fries. It has been under increasing pressure from consumer advocates and some public officials to make the change.

The new oil is canola-based and includes corn and soy oils.

CEO Jim Skinner told shareholders at the annual meeting at its headquarters in Oak Brook, Ill., that the new oil has been in use in U.S. restaurants for a few months now for french fries, hash browns, chicken, filet of fish and biscuits.

He said McDonald's is on schedule to convert to the new oil by year's end for its remaining baked items, pies and cookies.

Skinner said the company decided not to advertise the changes.

McDonald's Corp. has nearly 14,000 restaurants in the United States.

Its shares fell 32 cents to $58.46 in late morning trading.