Microsoft is slowly starting to roll out its new Intel-based Surface 3 tablets that come with 4G LTE built-in.

The first Surface 3s with built-in 4G LTE were rolled out in Japan with partner Y!Mobile two weeks ago, according to a July 1 post on Microsoft's Surface blog.

Starting July 3 in Germany and the U.K., Microsoft will make its first Surface 3 with LTE models available to business customers. Some unspecified time after that date, Microsoft will add Surface 3 models with 4G LTE in France and Spain.

The initial set of supporting carriers will include Deutsche Telekom in Germany, Orange Business Services in France, as well as O2 in the U.K. and Movistar in Spain.

Initially, in order to buy these 4G LTE Surface models, customers will need to be a business customer or partner operator.

Following availability to business customers in these first few markets, Microsoft is still planning to offer 4G LTE-enabled Surface 3 tablets at retailand through commercial resellers in France, Germany, the U.K. and the U.S. This will happen "in the coming weeks," according to company officials.

Back in April on Reddit, the Surface team confirmed an unlocked version of Surface 3 will be available at some point. There are still not many specifics about when/how these 4 G LTE Surface 3 devices will be out.

In March, when Microsoft unveiled the Surface 3 tablets, company officials said the 4G LTE model would be available through T-Mobile and Verizon Wireless in the U.S., "later this year." Microsoft execs have said more details on availability and markets of these devices would happen "in the coming months."

The 10.8-inch Surface 3 with 4G LTE will be available in two models: 64 GB and 128 GB, both with 4 GB of RAM and running Windows 8.1 Professional, with the option of upgrading for free to Windows 10. Earlier this year, Microsoft execs said the inclusion of 4G LTE would add an extra $100 to the $500 to $600 base price of the Surface 3.