EARNINGS : Apple Earns $131.7 Million in Third Quarter : Technology: The firm rebounds from a loss a year earlier despite fierce industry competition.

Despite fierce competition in the global personal computer business, Apple Computer Inc. Thursday reported third-quarter income of $131.7 million, or $1.07 a share, contrasted with a loss of $53.1 million, or 44 cents, last year.

It took a $138.9-million restructuring charge in the year-ago quarter.

Apple said sales rose to $1.74 billion in the quarter from $1.53 billion a year earlier.

Its earnings were in line with analysts’ estimates.

After Apple took a $224-million restructuring charge a year ago, it formed partnerships with former rival International Business Machines Corp. in software, entertainment and advanced microprocessor technology.

Chairman John Sculley said Apple remains strong in its core business of computers, software and peripheral devices.

He said it already has sold 300,000 PowerBook portable computers and expects to top $1 billion in sales in the products’ first year.

But Sculley said profit margins remain under pressure because of competition in the industry.

Gross margins slipped slightly, to 44.3% from 45.8% last year, reflecting that competition, the Cupertino, Calif.-based firm said.

“We must remain vigilant in managing our operating expenses to meet this challenge over time,” Sculley said.

He said Apple plans to open as many as 1,800 retail outlets in the United States by the end of 1992, continuing its new emphasis on consumer marketing.

“We continue to open new channels to reach new customers, especially in consumer markets,” Sculley said.

For the first nine months of its fiscal year, Apple said it had earnings of $432.8 million, or $3.52 a share, compared to $228.6 million, or $1.91, a year earlier. Revenue rose to $5.32 billion from $4.80 billion.