“Stay very close to your clients,” and, “Don’t stop selling.”

Managers at Aon Corp., Chicago (NYSE:AON), have given that message to employees at the Aon Consulting unit in a memo filed with the U.S. Securities and Exchange Commission that discusses Aon’s proposed $4.9 billion acquisition of Hewitt Associates Inc., Lincolnshire, Ill. (NYSE:HEW).

“Our competitors will be anxious to convince [clients] that we are distracted,” Aon managers say in the memo. “Let’s prove them wrong… Continue your focus on serving our clients exceptionally well.”

Aon managers acknowledge that employees may have concerns about the deal.

One of the questions Aon managers address is, “Will there be any layoffs as a result of the merger?”

“In the coming weeks and months we will be reviewing the combined company’s workforce so that we can best align our resources with the new size and scope of our combined business and continue to best serve our clients and markets,” managers say. “As in any transaction, there inevitably will be some redundancies identified, and any such changes or redundancies will be based on a fair and reasonable approach.”

Elsewhere in the memo, managers say, “As with any deal of this magnitude, there will be a plan to take out redundant costs to make the combined organization more efficient. As you would expect, these efforts will be focused in areas like real estate, infrastructure costs, and overlapping leadership and corporate services functions. None of these decisions can be made until we have officially closed the transaction and Aon Hewitt is operating as one company. It is inevitable that there will be some job losses, but we will handle these situations with fairness and respect for those associates.”

But Aon managers say they do not expect to make any near-term changes in Aon’s benefits and compensation as a result of the dea.

“Aon remains committed to providing a competitive compensation and benefits package for all colleagues that will allow us to attract and retain the talent needed to drive the firm forward successfully,” managers say.

Aon will hold town halls at several offices in the next few weeks to “share the excitement and answer questions.”

Strict rules govern what Aon and Hewitt can do together before the transaction completed, and the companies must compete vigorously against each other when they encounter each other in a sales situation, managers say.