UPDATE 1-HP buys IBRIX as it expands storage business

* HP buys privately held storage software maker IBRIX

* Deal comes amid wave of M&A in storage industry

* IBRIX clients include DreamWorks, Caterpillar, JPMorgan

BOSTON, July 17 (Reuters) - Hewlett Packard Co (HPQ.N) is buying privately held storage software maker IBRIX as it looks to catch up with IBM (IBM.N) and EMC Corp (EMC.N) in the $20 billion market for corporate data storage equipment.

HP did not disclose terms of the transaction, which was announced on Friday.

The move gives HP control of a technology that companies use to quickly access large quantities of data for important business applications. IBRIX has about 175 customers, including Steven Spielberg's DreamWorks Studios, Caterpillar Inc (CAT.N) and JPMorgan Chase & Co (JPM.N).

The small acquisition -- IBRIX has 53 employees -- comes as merger activity heats up in the storage industry, which analysts expect to grow faster than the rest of the tech industry.

EMC won a bidding war against NetApp Inc (NTAP.O) for specialty storage equipment maker Data Domain Inc DDUP.O this month. Broadcom Corp (BRCM.O) offered to buy storage networking equipment maker Emulex Corp (ELX.N) but was rejected.

IBRIX's biggest resellers include EMC and Dell Inc (DELL.O). An HP spokesman declined to say how HP would handle these relationships after the close of the acquisition.

HP is the third-largest provider of external disk storage equipment after market leader EMC and No. 2 player IBM. Dell is fourth.

HP hired former EMC executive David Donatelli in May to spearhead efforts to expand its storage business. That plan hit a snag after EMC persuaded judges in Massachusetts and California to temporarily bar him from managing HP's storage division, citing a non-compete clause in his contract. (Reporting by Jim Finkle; Editing by Steve Orlofsky)