NEW YORK (AP) — Worldwide shipments of tablet computers slowed down in the second quarter because Apple didn't release a new model of its trend-setting iPad, research firm IDC said Monday.

Shipments totaled 45.1 million units in the April-June period, down nearly 10 percent from the first three months of the year. Still the second-quarter total is up nearly 60 percent from a year ago, a sign that the market continues to grow.

"A new iPad launch always piques consumer interest in the tablet category and traditionally that has helped both Apple and its competitors," said Tom Mainelli, a research director at IDC. "With no new iPads, the market slowed for many vendors."

Apple normally releases a new iPad in the spring, but it has moved toward updating products in the fall to take advantage of the lucrative holiday shopping season. That means people who want iPads may be holding out for a new model. Samsung and other rivals have released new tablet models this spring, but IDC says those launches didn't get the spillover boost that a new iPad would have provided.

Mainelli said he expects weakness to continue in the July-September period, but tablet shipments should pick up again in the holiday quarter, when Apple and others are expected to release new products.

Besides a new iPad, Amazon.com Inc. is likely to refresh its Kindle Fire line, while Google Inc. is expected to come out with a new 10-inch Nexus model. The company released a new 7-inch Nexus last week.

Apple remains the leading maker of tablets, with 14.6 million shipped in the April-June period. But as disclosed in the company's earnings report last month, shipments fell 14 percent from a year ago. IDC says Apple's market share fell to 32 percent in the second quarter, compared with 60 percent in the same period in 2012.

Samsung Electronics Co., maker of the Galaxy line of phones and tablets, saw shipments nearly quadruple to 8.1 million in the second quarter. That gave Samsung a market share of 18 percent, up from 7.6 percent a year earlier.

AsusTek Computer Inc., which makes the Nexus 7 for Google along with its own branded tablets, was No. 3 with 2 million tablets. It was followed by Lenovo Group with 1.5 million and Acer Inc. with 1.4 million. Microsoft Corp., maker of the Surface tablets, dropped out of the top five after coming in at No. 5 in the first quarter, according to IDC. Amazon also lost its top-five status. It had been No. 4 in the first quarter.

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  • Apple iPad Mini

    The most expensive of the small tablets is also the prettiest. Its exquisitely machined metal rim sets it well apart from competing tablets clothed in plastic and rubber. It's also thin and light, despite having a screen that's 40 percent bigger than other "small" tablets. But the quality of the screen doesn't quite measure up to the competition. It has fewer pixels than other small tablets, and they're spread over a larger area, making for a relatively coarse, pixelated look. On the other hand, the Mini has two cameras, front and back, which is a rarity. Where the Mini really wins is in third-party apps: it's the only small tablet that has access to Apple's App Store, with a superlative selection of high-quality apps. It's an excellent addition to the household that's already hooked on iPhones and full-size iPads. For those not wedded to the "Apple system," the other tablets merit a close look. (starts at $329 for 16 gigabytes of storage)

  • Amazon Kindle Fire HD

    A year ago, the Kindle Fire was the plucky, cut-rate tablet, the Dodge Neon to the iPad's BMW. This year, the gap in quality and features has narrowed considerably. The Kindle Fire HD has a better screen than the iPad Mini, and now sports a front-facing camera. The original Kindle Fire had none. In another nice touch, it has speakers on either side of the screen when it's held horizontally, making for much better stereo sound when you're playing a movie. The selection of content is narrower than for the iPad, since it's heavily slanted toward Amazon's services. Likewise, the selection of third-party apps is smaller than on the iPad or Google's Nexus 7. But there are enough games to thrill a kid for hours, and like Barnes & Noble's Nook, the Kindle can be configured with a special "kid mode" that shields them from racier content — and from messing up your settings. The Kindle Fire is especially useful for members of Amazon's Prime shipping service, since they get access to free streaming movies. On the other hand, anyone could be annoyed by the ads that appear on the lock screen. Getting rid of them costs $15. There's no option for cellular broadband, so you're limited to Wi-Fi connections. (starts at $199 for 16 gigabytes of storage)

  • Barnes & Noble Nook HD

    Barnes & Noble has paid a lot of attention to the screens on its Nooks. This year, it's clearly outdone the competition, with a screen that packs the pixels tighter than any other small tablet. It's very sharp and colorful, approaching the look of the Retina screen that graces the full-size iPad. The other strength of the Nook HD is that it has a slot for a memory card, meaning that you can expand the storage space for movies and music by 32 gigabytes for $25. It's the only tablet in our roundup with this feature. The downside is that the Nook HD is less of a general-purpose tablet and more of a consumption device for books and movies. It doesn't have a camera, so it's no good for videoconferencing. The selection of apps is the smallest. You'll find big names like "Angry Birds" here, but there is no depth to the catalog. There's also no option for cellular broadband. Still, the Nook is an excellent choice for avid readers, kids and others who won't be frustrated by the small selection of things like 3-D shoot-em-up games. (starts at $199 for 8 gigabytes of storage)

  • Google Nexus 7

    Frustrated that Amazon and Barnes & Noble were taking Google's Android software, gutting it and using it to power tablets that don't yield the search giant a red cent in advertising revenue or e-book sales, Google this year launched the first tablet under its own brand. The Nexus 7 has a power-house processor and a screen similar to that of the Kindle Fire HD. Since it runs stock Android, it has access to hundreds of thousands of applications written for Android smartphones, and it has more sophisticated multi-tasking abilities than the competitors, so it's easy to switch from program to program. Like the iPad Mini, it has a GPS chip for navigation. It has a front-facing camera for videoconferencing. There's a $299, 32-gigabyte version that can connect to AT&T's wireless network. The Nexus 7 is a great tablet for the technophile who would chafe at the restrictions imposed by competing manufacturers. But anyone will be able to appreciate it. In terms of kid-friendliness, it's beaten by Amazon and Barnes & Noble. (starts at $199 for 16 gigabytes of storage)