The BlackBerry PlayBook is currently only available as a Wi-Fi device.

Updated 5:17 P.M. PST with comment from RIM

RIM’s BlackBerry PlayBook tablet just can’t catch a break.

Sprint announced Friday that it will not be selling a 4G version of the PlayBook on its Wi-Max network.

“We apologize for any inconvenience but the BlackBerry 4G PlayBook Tablet that was announced in January for summer availability will no longer be coming to the Sprint network,” a Sprint representative told Wired.com in a statement. “This was a mutual decision between Sprint and RIM.”

The news was first reported by The Wall Street Journal.

AT&T and Verizon do not currently support the PlayBook on their networks. AT&T announced it would support the PlayBook’s “bridge” application, which is necessary for users to access e-mail and calendar functions, in July.

Without carrier support, RIM can only sell a Wi-Fi version of its product. It must be paired with a Blackberry phone in order to access a carrier’s 3G network. When the product was announced, future 3G and 4G models were promised.

RIM is coloring the announcement somewhat differently.

“RIM has decided to prioritize and focus its 4G development resources on LTE,” a RIM spokeswoman told Wired.com in a statement.

Sprint’s 4G network is based on Wi-Max technology, a competitor of AT&T’s and Verizon’s LTE-based networks.

Reception of the BlackBerry PlayBook has been less than enthusiastic generally. The tablet has struggled with displaying Flash, which delayed the device’s initial launch a month. RIM initially said it planned to release the PlayBook on the three largest U.S. carriers (Verizon, AT&T and Sprint). In May, Wired.com reported that Sprint was delayingthe BlackBerry PlayBook release.

Apple’s highly successful iPad is supported by both AT&T and Verizon, and reported sales of approximately 9.3 million units in the first quarter of 2011. The Wi-Fi-only PlayBook shipped 500,000 units over that same time period, and the Motorola Xoom saw only 440,000 tablets ship.

Mike Isaac contributed to this report.