Amazon Web Services is approaching a $10 billion-a-year business

Amazon Web Services, the company’s cloud computing arm, continues to grow rapidly and is the company’s most profitable segment.

Amazon said today that AWS generated $2.6 billion in revenue during the first quarter, representing 64 percent year-over-year growth. That’s a slight deceleration from 69 percent growth during the fourth quarter and roughly in line with Wall Street’s expectations.

Over the past four quarters, AWS generated $8.9 billion in revenue for Amazon. That trailing-twelve-months figure is likely to pass $10 billion sometime this year.

AWS also continues to be a profit bright spot for Amazon. The segment’s operating income, after stock-based compensation, reached $604 million during the first quarter, up from $195 million during the year-ago quarter. That was better than the company’s North America commerce segment ($588 million operating income) or international ($121 million operating loss).

Stock-based compensation (“and other” expenses) for AWS reached $112 million during the first quarter, up from $70 million a year ago.