Private equity firm KKR & Co LP is nearing a deal to buy industrial machinery maker Gardner Denver Inc and could announce the agreement in the next few days, two people familiar with the matter said on Monday.

The two parties have been negotiating a final deal price and other last-minute details over the past week, after KKR bid $75 per share, or nearly $3.7 billion, for Gardner Denver, on Feb. 21, the people said.

Gardner Denver shares rose 3.5 percent to close unofficially at $73.51.

The final price could not be learned, but Gardner Denver's board sought a higher price from the buyout firm, the people familiar with the matter said.

Negotiations are continuing and could still fall apart, said the people, who asked not to be named because the matter is not public. Representatives for KKR declined to comment. Gardner Denver could not be immediately reached for comment.