Shelby Coffey III, who became editor of the Dallas Times Herald in January after resigning as editor of U.S. News & World Report, has agreed to become deputy associate editor for most of the feature sections of the Los Angeles Times, according to Times Editor William F. Thomas.

According to sources at the Times, Coffey's move would put him in the "sweepstakes," as it is sometimes called in Los Angeles, with other key editors considered possible successors to Thomas. Thomas has said that he plans to retire in 1989 at age 65.

Coffey, 39, who worked for The Washington Post for 17 years, has become something of an editorial nomad in the past 16 months -- buffeted by reported disagreements with U.S. News owner Mortimer B. Zuckerman, who named himself editor in chief shortly after Coffey arrived in March 1985, and by economic problems in Dallas where the Times Herald is No. 2 in a bitter race with The Dallas Morning News.

Just as Coffey seemed to be "taking hold" in Dallas, as one Times Herald reporter put it, the Times Mirror Corp., which owns both the Times Herald and the Los Angeles Times, announced plans to sell its Dallas paper to newspaper entrepreneur William Dean Singleton.

Singleton, who said he wanted to make Dallas the flagship of his small media chain, said at the time that he'd asked Coffey to stay on as editor. Coffey said then that he wanted to talk with his family about whether to remain with Singleton, investigate other jobs within the Times Mirror Corp. or look into offers with other media companies.

A key source at the Times in Los Angeles said the new position, which is very much like the job Coffey held at The Washington Post for many years, is "virtually equivalent" to the title of deputy managing editor. At that level are two of the other chief contenders for Thomas' job, according to a number of sources at the paper. They are Dennis Britton, deputy managing editor in charge of foreign, national and financial news, and Noel Greenwood, who runs the paper's large metropolitan staff.

Other names sometimes listed as contenders for the job of Los Angeles Times editor are Managing Editor George Cotliar and Foreign Editor Alvin Shuster.

Coffey, who praised the talents and energy of the Times Herald management and staff, said that he decided to leave because "this opportunity with the Los Angeles Times and Times Mirror, as well as family considerations, took precedence."

Thomas said that in Coffey's new job he would report to Associate Editor Jean Sharley Taylor. Some Times sources saw the change, including the creation of a new job for Coffey, as an indication that Taylor was ceding some of her duties as the longtime, powerful head of the features sections for the paper.

Coffey's territory would include the daily feature section called "View," as well as portions of the paper devoted to travel, real estate, television, book and movie reviews and food. He will also be in charge of the paper's new, but struggling, Sunday magazine.

"All of it is part of Shelby's background," said Thomas.

Thomas declined to say whether the new job makes Coffey a contender in the battle for succession at the Times.

"It brings him into the paper, and what happens in three years is anybody's guess," said Thomas.