EMC on Monday increased its offer for Data Domain by 12 percent to $33.50 a share, valuing the specialty storage maker at $2.4 billion and raising stakes in a bidding war against rival NetApp.

EMC also removed a breakup fee from its offer for Data Domain and said it was ready to complete a deal within two weeks.

The battle for Data Domain, which began with an offer of $25 a share from NetApp,  has grown increasingly acrimonious. Last month, EMC took out a full-page ad in The San Jose Mercury News explaining to Data Domain’s employees why a deal with EMC is better than one with NetApp.

Data Domain, for its part, has maintained that a deal with NetApp makes more sense and raised questions about EMC’s motives. In an interview with The Mercury News, NetApp’s chief marketing officer called EMC’s bid a “defensive move to try to limit Data Domain’s growth.”

In an environment where getting any deal done is proving to be very difficult, this is a rare bidding war. And given the shaky markets, investors might prefer a cash bid.

Additionally, as the amount of data that companies store — and the cost to store it — is on the rise, demand for data-reduction technology, which boosts the efficiency of data storage equipment by deleting duplicate pieces of information, is likely to increase as well. This bidding war could drag on.