EMC Corp. (EMC) extended its $1.9 billion all-cash bid for Data Domain Inc. (DDUP), as only a very small portion of the stock had been tendered as of Friday.

EMC bid $30 a share for Data Domain earlier this month, several weeks after the company already agreed to data-storage company NetApp Inc.'s (NTAP) $1.5 billion cash-and-stock offer. NetApp then boosted its bid to match EMC on a per-share basis.

Data Domain's board, meanwhile, urged shareholders two weeks ago to reject EMC's bid.

Shareholders seemed to thus heed Data Domain's call, as EMC disclosed that about 174,645 shares of Data Domain common stock, representing about 0.28% of the common stock outstanding, had been tendered as of 3:30 p.m. EDT Friday.

As a result, the offer, which was to expire at midnight EDT on June 29 was extended to midnight EDT on July 10.

"EMC's $30 per share all-cash offer remains superior to NetApp's stock and cash offer, and very importantly, delivers Data Domain stockholders the price certainty and price protection its management team and board stated as important priorities during their negotiations with NetApp," said EMC Chief Executive Joe Tucci.

A Data Domain representative wasn't immediately available for comment.

Data Domain specializes in technology for "deduplication," or avoiding repeated storage of the same data. The technology can reduce demand for storage devices, and it is a selling point at a time when corporate computer chiefs are trying to cut hardware costs and save floor space and electricity use in computer rooms.

Data Domain's shares were up 0.7% to $33.36 in after-hours trading. EMC's shares were even at $13.51, as was NetApp's stock at $19.40.

- By John Kell, Dow Jones Newswires; 201-938-5285; john.kell@dowjones.com