Green Mountain Coffee Roasters Inc raised its all-cash offer to buy Diedrich Coffee Inc by $2 a share, overshadowing rival Peet's Coffee & Tea Inc's enhanced bid.

Diedrich, a licensee of Green Mountain's K-Cup refills for its single-cup Keurig brewer system, said its board was considering Green Mountain's revised offer of $32 a share and has informed Peet's about this latest development.

On Monday, Peet's had raised its cash-and-stock offer to buy Diedrich to $32 a share, or $261 million.

However, Peet's shares closed down 13 percent on Monday, making the offer worth about $30.41 per Diedrich share.

Green Mountain expects the deal to be neutral or add slightly to earnings during the first 12 months following the close, excluding one-time transaction expenses, and add to its earnings thereafter.

Peet's can negotiate an amendment to its current merger agreement with Diedrich by Friday, Diedrich said.

Separately, Peet's said Diedrich's board has sought additional time to analyze Green Mountain's proposal.

Shares of Green Mountain were down 2 percent, while those of Diedrich were down 1 percent. Peet's stock was trading up 1 percent Tuesday morning at Nasdaq.

(Reporting by Renju Jose; Editing by Deepak Kannan, Anne Pallivathuckal, Anil D'Silva)