Microsoft Corp. reported a dip in quarterly profit Thursday as sales of personal computers lagged expectations and Apple Inc.’s iPad began to eat away at the fringes of its core market.

The world’s largest maker of software, which powers more than 90 percent of the world’s computers, reported fiscal second-quarter profit of $6.63 billion, or 77 cents per share. That compared with $6.66 billion, or 74 cents per share, a year earlier. The per share figure was higher due to a reduction in shares outstanding from last year.

Year-ago profit was boosted by a one-time deferral of revenue from the launch of the hot-selling Windows 7 operating system.

Wall Street was expecting 68 cents per share profit, according to Thomson Reuters I/B/E/S.

Sales rose 5 percent, to $19.95 billion, helped by strong sales of its Kinect hands-free gaming system, handily beating analysts’ average estimate of $19.15 billion.

Microsoft’s shares were flat after rising on Nasdaq. They are down about 3 percent in the last 12 months.