AT&T Inc. and Sierra Wireless Inc. Tuesday announced a new laptop cellular data card called the AT&T USBConnect Mercury. It is the smallest of the cellular data cards that AT&T offers for its 3G network.

The Mercury will be free for customers who purchase a two-year cellular data plan worth at least US$60 a month. AT&T offers several data plans, and for $60 a month, a customer can receive as much as 5GB of data use in the U.S.

One new feature of the Mercury, which looks like a USB flash drive, is an integrated microSD slot to give users portable storage. It was designed and manufactured by Sierra Wireless. Mercury's predecessor was the High Speed Packet Access-capable USBConnect 881, an AT&T spokesman said Tuesday.

The Mercury, which operates under HSPA, can be used with AT&T's North American or global data plans. The North American plan provides 100MB of monthly use in Canada and Mexico, plus 5GB in the U.S. for $109.99 a month. Meanwhile, AT&T's global plans start at $139.99 a month for 100MB of usage in 67 countries, plus 5GB in the U.S. Or, customers can receive 200MB of monthly usage in the same 67 countries for $229.99 a month.

That cost is more than what AT&T now offered Apple Inc. iPhone users in an international data roaming plan unveiled last week. One of the new iPhone plans costs $119.99 a month for 100MB of data use, while the other costs $199.99 a month for 200MB. Both plans apply to 67 countries.