EarthLink, which is scheduled to announce its fourth quarter earnings report on Wednesday, announced today that it is laying off one quarter of its workforce.

The Internet Service Provider said some 1,300 employees would lose their jobs under the cutbacks. Most jobs affected will be at call and technical support centers in Dallas, Sacramento and Seattle, which will be closed.

A technical support center in Pasadena, CA also will be closed, the company said.

“Our plan to streamline our call center operations will positively impact our financial performance and help us to better compete in a rapidly changing marketplace,” said Garry Betty, chief executive officer of EarthLink.

EarthLink (Nasdaq: ELNK) announced the layoffs Tuesday afternoon before markets closed.

This morning, EarthLink announced fourth quarter results, saying revenues increased $20 million, to $347.9 million, over 2001 figures. The total was in line with projections.

Helping drive up revenues was a growing subscriber base of high-speed DSL and cable customers. EarthLink said it added 98,000 in the quarter.

Losses were $32.9 million for the quarter, down from $73.9 million in 2001.

The company’s stock surged 30 cents, or 5 percent, to close at $5.96 on Tuesday.

EarthLink recently closed a call center in Phoenix.

EarthLink estimated that the latest rounds of closings and workforce reductions would save the company $20 million a year.