TORONTO — Struggling BlackBerry maker Research in Motion Ltd. said today that it will cede most consumer markets and focus on business customers.

RIM has been struggling as Americans are abandoning their BlackBerrys for flashier touch-screen phones such as Apple’s iPhone and models that run Google’s Android software. BlackBerrys have been popular among business customers, in large part because of their security. But RIM has had limited success trying to enter consumer markets in recent years.

“We plan to refocus on the enterprise business and capitalize on our leading position in this segment,” CEO Thorsten Heins said. “We believe that BlackBerry cannot succeed if we tried to be everybody’s darling and all things to all people. Therefore, we plan to build on our strength.”

Also today, RIM said former co-CEO Jim Balsillie has resigned from its board. David Yach, chief technology officer for software, and Jim Rowan, chief operating officer for global operations, also are leaving in a management shakeup.

Heins made the remarks during a conference call after RIM announced quarterly results that fell short of Wall Street expectations.

RIM said it had a net loss in the latest quarter because of writedowns for the declining value of its brand and its PlayBook tablet inventory. Net loss was $125 million, or 24 cents a share, in the quarter that ended March 3. This compares with $934 million, or $1.78 per share, a year ago.

Adjusted income was 80 cents per share, a penny short of expectations from analysts polled by FactSet.

Revenue fell 25 percent to $4.2 billion from $5.6 billion. Analysts were expecting $4.54 billion.