Affiliated Computer Services' founder Darwin Deason said he and investment fund Cerberus Capital Management have offered to buy the computer services company for about $5.9 billion.
Deason, chairman of ACS, and Cerberus said in statement they submitted a proposal to buy all the shares at $59.25 each, equivalent to a 15.5% premium over its closing price on Monday.
The shares were recently up 17.3% on the news.
Based on the 100 million shares outstanding in ACS's latest regulatory filing, the offer is worth about $5.925 billion.
The deal would be worth $8.2 billion including debt that would either be refinanced or remain outstanding, the statement said.
"I believe that this offer and our proposed process will maximize value for all of ACS's shareholders, and I am very pleased to be working with Cerberus to bring this proposal to the ACS Board of Directors," said Deason in a statement.
He added he would keep the company's "valuable employee base," and would continue as chairman following the deal.
Citigroup Global Markets has provided a "highly confident" letter stating it is highly confident of its ability to raise the debt necessary to complete the transaction.
Deason would continue as executive chairman after a buyout, the statement said.