The service, which allows BlackBerry users to send each other text and multimedia files and see when they are delivered and read, is widely known and even promoted by RIM via the shorthand BBM.

That has proven an encumbrance to BBM Canada, which measures radio and television audience data and expects its day in a Federal Court against RIM by February.

The company's chief executive, Jim MacLeod, said he wants RIM to stop advertising the BBM moniker but would also consider changing his much smaller company's name, for a price.

"We have to be practical, they operate worldwide, we don't. But we're not prepared to just walk from our name," MacLeod said.

RIM seems equally determined to keep using the BBM name and not to pay MacLeod's company anything.

"We believe that BBM Canada is attempting to obtain trademark protection for the BBM acronym that is well beyond the narrow range of the services it provides and well beyond the scope of rights afforded by Canadian trademark law," it said in an emailed statement.

RIM has launched its BBM Music song-sharing service in recent months, and heavily promoted third-party apps that tie into its instant messaging product, which boasts some 50 million active users.

BBM Canada was established in 1944 as the Bureau of Broadcast Measurement. It changed its name to BBM in the 1960s and to BBM Canada in the early 1990s, MacLeod said. The company, owned by a collection of broadcasters and advertisers, has annual revenue of around $50 million. RIM's sales were more than $5 billion last quarter.

"I'm sure to a really big company this looks like relatively small numbers, but to us it's a big deal," said MacLeod. BBM Canada employs around 650 people, compared with RIM's roughly 17,000.

Earlier this month RIM dumped the "BBX" name for its new operating system after being served with an injunction in a trademark fight with U.S.-based Basis International. RIM has renamed the platform as BlackBerry 10.

Industry Canada denied RIM's 2009 request to register the BBM trademark, saying the name was already in use, but has granted RIM until January 5 to respond.

BBM Canada launched its legal action late last year.

MacLeod said his company contacted RIM in July, soon after RIM launched a large-scale BBM advertising campaign. In response to BBM Canada's cease-and-desist letter RIM said there couldn't possibly be any confusion between the two names - a similar tactic was later used in the BBX spat.

RIM repeated that line of argument in Friday's statement.

"The services associated with RIM's BBM offering clearly do not overlap with BBM Canada's services and the two marks are therefore eligible to co-exist under Canadian trademark law. The two companies are in different industries and have never been competitors in any area."

MacLeod sought a meeting to discuss the issue with RIM co-CEO Jim Balsillie several months ago, but said he has received no response.

McLeod pointed out that RIM had even taken legal action of its own against software startup Kik Interactive over its instant messaging service that includes claims of trademark infringement.

"It's a trademark they don't even own, it's ours," MacLeod said.

(Reporting by Alastair Sharp; editing by Rob Wilson)

• A Permanent Economic Emergency