Jeff Rice is about to lose his job. He's the corporate-marketing manager for a minor league hockey team in Worcester, Mass., that's being sold to businesspeople in Peoria, Ill. If he stays in his job until the hockey season ends next year, he'll get two months' salary as severance. He might also find a job at the company that sold the team.

But Mr. Rice, who is 30 years old and has two children, isn't taking his chances. He has already started job hunting and plans to take the first good job that comes along, even if it means forfeiting the severance.

"The job market is still tight -- it still takes awhile to find new jobs," he says. "I don't want to risk turning something down and not being able to find something."

It's a quandary many workers face when their employers go through a merger or sale: Should you try to jump ship right away and give up a cushy exit package? Or should you wait in hopes of a fat severance payment but risk not being able to find another good job?

The dilemma affects many workers as industries continue to consolidate and wring efficiencies through giant mergers. Earlier this month, Kmart Holding Corp. announced plans to buy Sears, Roebuck & Co. Earlier this year, J.P. Morgan Chase & Co. bought Bank One Corp. for $58 billion.

Career experts say that as soon as you hear rumors of a merger or sale, you should start at least preparing for a job search. Update your résumé and strengthen relationships with people who could help you find a new job. You don't have to tell them you're looking for a job yet, just build up your network. Start discreetly collecting home-contact information from references -- you'll need to reach them outside work if they get laid off too. At this time of year, try using holiday cards as a guise to get home addresses, suggests Allison Hemming, president of The Hired Guns, a New York interim-staffing company.

"You never know what's going to happen," cautions Brad Karsh, president of JobBound, a Chicago career-counseling company. "The situation is highly volatile."

One of the most difficult tasks in a merger is determining how vulnerable your job is. Companies typically aim to reduce costs by eliminating duplicate jobs. Corporate-headquarters jobs in areas such as accounting, legal services, human resources and public relations are often a first target for cutbacks.

Conventional wisdom holds that employees at the acquiring company are safer. But that's not always the case, so it's important to analyze the politics of your merger carefully. Sometimes, the dominant company at the beginning of a merger doesn't remain so. When America Online bought Time Warner in 2001 to create AOL Time Warner, the deal symbolized the ascendancy of "new media." But after the tech bubble burst and America Online's business stumbled, the balance of power shifted back toward Time Warner. The company even dropped "AOL" from its name.

In the Kmart-Sears deal, the firms haven't detailed their work-force plans yet. At an investor presentation after the deal was announced, Sears Chief Executive Alan J. Lacy said: "Certainly there will be some head-count changes that come out of this, particularly as we consolidate over time some of the administrative functions. But I think it's important to say that we've got two brands that both need to be very well supported going forward."

But analysts, consultants and recruiters are already making predictions about where the work forces might be trimmed and which side's employees are more vulnerable. In Kmart's favor is the fact that most of Kmart's senior brass came from outside less than two years ago and are well-regarded in such areas as finance, merchandising and marketing. Kmart's organization is already pretty lean after having emerged from Chapter 11 bankruptcy-court protection last year.

However, some observers think Kmart's employees may be more vulnerable in certain areas. Retail analysts say Sears's distribution and supply-chain operations are stronger than Kmart's, so Sears employees in those areas may be more secure. "In that middle-management swath that has something to do with the back end of operations, the Sears people are going to wind up having more importance and hold on to their jobs, probably more so than the Kmart people," predicts Richard Hastings, retail analyst at Bernard Sands in New York.

The new company will be called Sears Holdings Corp. and its base will be Sears's current hometown, Hoffman Estates, Ill., which also could give Sears employees an edge, although Kmart will continue to have a "significant presence" in Troy, Mich., the companies said.

Mark MacLeod, now 28 years old, took an educated gamble in 2002 when he learned his employer, ad agency Leo Burnett in Chicago, would be sold to French firm Publicis Groupe SA. He had worked at Leo Burnett for about a year and a half and felt ready to try something different. He was interested in marketing consulting and had done some research into changing jobs even before the deal. So he sat down with a supervisor. If layoffs were planned, Mr. MacLeod said, he was interested in negotiating an exit package. Mr. MacLeod got three months' salary as severance, took some time off and three months later got a job at a small marketing consultancy.

"I wouldn't have left Burnett so blindly if I didn't have a pretty good idea that things would work out," he says.