OTTAWA (Reuters) - Research In Motion said Thursday that it has isolated and resolved the issue that delayed email service for some North American BlackBerry customers this morning.

RIM said in a statement that some clients may continue to experience delays as email queues are processed. The issue had not affected phone service, browsing and “PIN-to-PIN messaging”.

The company, which reports third-quarter financial results after markets close Thursday, said it is continuing to investigate the cause of the problem.

Independent technology analyst Carmi Levy said it appears the outage affected individual consumers and small businesses rather than major corporate or enterprise customers that pay more for a different type of service.

“The timing couldn’t be worse. In the run-up to the holiday season you never want to receive this kind of black eye,” Levy said in an interview.

“The smartphone market has never been more competitive. No company can afford to have this kind of large-scale outage, because certainly that plays in customers’ minds when they make their platform choices.”

After RIM had major outages in February 2008 and April 2007, customers raised concerns over service stability. The company said it would investigate and improve reliability to avoid future crashes, but did not disclose details, Levy said.

“They’ve divulged relatively little information, relatively late in the game, and for most customers that has not been enough,” Levy said.

Shares of RIM were down 80 cents, about 1.2 percent on Nasdaq at $63.87 at midday Thursday and up 5 Canadian cents at C$68.44 on the Toronto Stock Exchange.