The decision over the next standard for mobile sim cards has become bogged down in a spat over patents.

Nokia, Motorola and RIM are locked in a pitch battle with Apple over rival proposed formats for the new nano-sim standard.

Nokia, which is strongly pushing its own design, has threatened to withhold crucial patents relating to communication and processing in mobile devices if Apple’s proposed design is chosen.

Earlier this week, RIM accused Apple of attempting to influence the vote, claiming that three Apple employees had re-registered for the Institute under unaffiliated companies.

The verdict, previously expected this week, will be decided by a vote of European Telecommunications Standards Institute (ESTI) members, telecoms providers and manufacturers.  

This will now take place in June. Such decision processes are normally kept under wraps by the Institute, though “given the strong media interest, exceptionally ETSI has decided to communicate on this ongoing process.”

While neither proposal is available to the public, and with both sides claiming that theirs is technically superior, it’s difficult to weigh the various pros and cons of each.

Nokia says its own design is the more compact, and that Apple’s design, using a tray loading mechanism, will take up more room and does not comply with required specifications on size.

Nokia’s case has won the backing of Motarola Mobility, with its big brother and proposed acquisitor Google standing in the shadows, and RIM.

Apple, which in the past has suggested dropping sim cards altogether, says its card will be made available on a royalty free basis to other manufacturers.