Casey's General Stores, the target of a takeover bid by a Canadian rival, Wednesday urged its shareholders not to act until it has reviewed Alimentation Couche-Tard's improved offer of $38.50 US a share, or $2 billion.

The Iowa-based convenience store chain said it would make a recommendation in due course.

A Casey's store sign shown in Des Moines, Iowa, in October 2006. Alimentation Couche-Tard Wednesday increased its bid for its American rival.A Casey's store sign shown in Des Moines, Iowa, in October 2006. Alimentation Couche-Tard Wednesday increased its bid for its American rival. (Charlie Neibergall/Associated Press)

Casey's has rejected all previous offers and declined to negotiate with Couche-Tard.

The new offer is 50 cents a share higher than the amount Casey's said it will pay to buy back more than one quarter of its own stock in an attempt to block the sale.

Couche-Tard said its revised offer is a 32 per cent premium over Casey's one-year average closing share price as of April 8, when the first takeover attempt was made.

Casey's shares closed up $1.03, or 2.7 per cent, to $38.65 on the Nasdaq. Shares of Couche-Tard added 91 cents, or four per cent, to $23.80 on the Toronto Stock Exchange.

With files from The Canadian Press