EMC has increased its offer to acquire storage vendor Data Domain from $1.8 billion to $2.1 billion (£1.1 to £1.28 billion) in its latest effort to shove aside original bidder NetApp.

The all-cash offer is "clearly superior" to the $1.9 billion NetApp proposal, which includes stock and cash, EMC CEO Joe Tucci said in a letter to the Data Domain board that EMC publicly released. EMC is also ready to close the deal within two weeks, which is faster than NetApp, Tucci added.

In a statement released later on Monday, NetApp CEO Dan Warmenhoven said the company's board "will carefully weigh its options."

The company "will provide an update shortly," Warmenhoven added.

Data Domain makes de-duplication storage systems, which pinpoint redundant data and help companies save disk space.

NetApp had originally entered an acquisition agreement with Data Domain in late May, but EMC subsequently moved with counteroffers in an effort to squelch the deal.

Citing a number of factors, including a $57 million termination fee Data Domain would likely have to pay NetApp, Data Domain's board of directors has recommended shareholders reject EMC's entreaties.

To that end, the latest EMC bid does not include such a fee and other "deal protections," according to EMC.

EMC is also ready to close the deal within two weeks, which is faster than NetApp, Tucci added.

It remains to be seen what effect the new bid will have on the Data Domain board. A company spokesman declined to comment.

Meanwhile, NetApp is proceeding apace, announcing that it had cleared all necessary US regulatory hurdles to proceed with the acquisition. Data Domain shareholders are scheduled to vote on NetApp's offer on August 14, according to NetApp.

Data Domain makes deduplication storage systems, which pinpoint redundant data and help companies save disk space. The company and NetApp could not immediately be reached Monday.