WorldCom Inc.'s new chief executive, Michael D. Capellas, unveiled a 100-day plan yesterday that he said would put the telecommunications firm on track to file a reorganization plan with a federal bankruptcy court by April 15 and emerge from bankruptcy by midyear.

Capellas also began putting his stamp on the company yesterday by naming executives to two key positions -- Victoria Harker as acting chief financial officer and Grace Chen Trent as chief of staff. Both served with Capellas when he was president of Hewlett-Packard Co.

Capellas made the announcement in Orlando, where he was meeting with WorldCom's sales staff. The 100-day plan was short on details, but Capellas did say the company would renew its focus on small and medium-size business customers.

In an interview yesterday Capellas said WorldCom has noticed a loss in mid-size company customers since revealing massive accounting errors last June. "We have seen some erosion in the mid-market, and that is where we really need to step up," he said.

Capellas declined to provide specific numbers on the customer falloff, but it was the first time the company has revealed any significant declines because of its accounting scandal and subsequent bankruptcy filing. WorldCom has said it may have improperly accounted for up to $9 billion in a three-year period from 1999 to 2002.

During his presentation yesterday, Capellas noted that the company has reached a partial settlement with the Securities and Exchange Commission on fraud charges but that it is still the subject of a criminal investigation by the Justice Department. The company is also waiting for the results of a detailed internal report from outside attorney William R. McLucas, a former director of enforcement at the SEC.

McLucas's report, due next month, is expected to include a series of recommendations to prevent a repeat of past mistakes. Capellas said he is committed to implementing any recommendations in the report, even if it calls for the dismissal of employees because of improper activities. The comprehensive report is expected to cover not only the company's accounting problems, but also practices by some sales employees who allegedly boosted their commissions improperly.

Four WorldCom executives have already pleaded guilty to fraud-related charges. A fifth, former chief financial officer Scott D. Sullivan, has pleaded not guilty but continues to talk with prosecutors about a possible plea agreement in exchange for testimony against Bernard J. Ebbers, the company's founder and former chief executive. Ebbers has not been charged with any crimes.

Capellas also said yesterday that WorldCom will eventually change its name in an effort to separate itself from its now-tainted past. The company has conducted a brand analysis, which determined that the WorldCom name has suffered with consumers because of the scandal. Among the several names under consideration is MCI, the moniker of the Washington-based long-distance company that was absorbed by WorldCom in 1998.