NEW YORK (AP) -- Men's Wearhouse says it won't give Jos. A. Bank access to nonpublic information that it could use to assess whether to potentially raise its $2.3 billion buyout offer.

Shares of both companies fell in Monday premarket trading.

On Thursday, Jos. A. Bank Clothiers said it would consider boosting its bid if allowed access to nonpublic information. The Hampstead, Md., company also said it would drop its offer in two weeks if there continued to be no discussions on the proposal.

On Monday, Men's Wearhouse said its board met with external financial and legal advisors and determined it wasn't in its shareholders' best interest to give Jos. A. Bank access to the information.

Houston-based Men's Wearhouse maintains that Jos. A. Bank's $48-per-share offer significantly undervalues its business.