International Business Machines Corp.'s third-quarter earnings beat estimates, but the technology giant's stock fell as its revenue slipped year over year and missed market expectations.

The company's net income increased to $2.69 billion, or $2.94 per share, in the quarter that ended Sept. 30, from $2.73 billion, or $2.92 per share, in the prior-year period.

Non-GAAP earnings from continuing operations came in at $3.42 per share, exceeding the S&P Global Market Intelligence consensus normalized EPS estimate of $3.40.

Third-quarter revenue fell year over year to $18.76 billion from $19.15 billion, missing the S&P Global Market Intelligence estimate of $19.04 billion. Technology services and cloud platforms, IBM's biggest business segment, generated revenues of $8.29 billion, down from $8.46 billion a year earlier.

Revenues from the cognitive solutions segment fell 6% year over year to $4.15 billion in the third quarter, while global business services revenues went up 1% to $4.13 billion. Systems segment revenues also increased by 1%, to $1.74 billion, while global financing sales dropped 9% to $388 million.

IBM's earnings expectations for full-year 2018 were unchanged from its previous guidance. The company projected operating EPS of at least $13.80 on a non-GAAP basis, and EPS of at least $11.60 on a GAAP basis.

Shares in IBM were down 4.84% to $138.10 as of 4:22 p.m. ET. The stock earlier closed higher by 2.83%.