The number of new subscribers to RIM's Blackberry service has shown a sharp increase. The company said that customers are once again signing up for the mobile push e-mail service after the hiatus of its patent lawsuit.

"There's no question there's a resurgence setting up after the IPR overhang and hype going on in the market in the last six to nine months," Jim Balsillie, chairman and co-CEO for RIM said. Earlier this year, RIM settled a contentious patent lawsuit that had dragged down sales for the BlackBerry maker.

During its first fiscal quarter, RIM added 680,000 subscribers and shipped 1.2 million devices. RIM now has 5.5 million subscribers worldwide.

While revenues were higher than RIM expected, net income slipped. RIM reported US$129.8 million in net income for the quarter, compared to $132.5 million during the same quarter last year. The dip was due in part to an increase in operating expenses as RIM invests in new product development and international market expansion, RIM said.

For the quarter, 26 percent of customers were outside of North America, up from the previous year, Dennis Kavelman, RIM's chief financial officer said.

In its next fiscal quarter, RIM expects to add 675,000 to 700,000 new customers and increase revenue. Despite growing competition from an increasing number of providers of push e-mail services, including Microsoft, RIM said it hasn't yet felt an impact from the new players. "We're not seeing anyone taking any kind of share of what we have," Balsillie said.

In March, RIM agreed to pay $612.5 million to settle a lawsuit with NTP, which claimed that RIM infringed on some of its patents.

NTP had asked the court to require RIM to shut down its service in the U.S., a threat that RIM said explained a slow-down in new customer additions late last year. RIM is currently defending itself in a new patent dispute, this time from Visto.