NEW YORK (CNN/Money) - Federal prosecutors plan to seek an extension of the deadline to indict former ImClone Systems CEO Samuel Waksal on charges related to insider trading of company stock, a person close to the situation said Wednesday.

The Friday deadline is likely to be extended by two weeks to 30 days in an effort by the government to buy more time to reach a plea agreement with Waksal and his lawyers, the source said.

Waksal may plead guilty to insider trading-related charges in order to protect others in his family from being indicted in the case, the report said. His father and daughter also sold shares and could be indicted, the Wall Street Journal reported Wednesday.

Attorneys for Waksal have met with prosecutors to discuss a possible settlement, the person said. However, talks are in the preliminary stages and no agreement is imminent.

The former ImClone CEO is under investigation for allegedly selling shares in the company after learning that the Food and Drug Administration had rejected an application for ImClone's cancer drug as well as informing family members and friends. Homemaking entrepreneur Martha Stewart, a friend of Waksal, also in being investigated for selling nearly 4,000 shares in the company the day before the news of the rejection was made public.

In this type of case, those involved must be indicted by a grand jury within 30 days or have a preliminary hearing at which the evidence is presented, the WSJ said.

Extension requests almost always are granted if both parties agree, which is likely, the Journal said.

A spokesman for Waksal declined comment. The U.S. Attorneys office for the Southern District of New York could not be reached for comment.

ImClone (IMCL: down $0.28 to $7.00, Research, Estimates) shares slipped more than 1 percent Wednesday.