(Adds details on offer, background) April 8 (Reuters) - APM...

(Adds details on offer, background)

April 8 (Reuters) - APM Human Services International (APM) said on Monday its largest shareholder Madison Dearborn Partners had offered to acquire all shares of the Australian employment services firm it does not already own for A$1.28 billion ($841.09 million).

The offer is for A$1.40 per share, a 14.1% discount to APM's last closing price on March 26, and lower than previous suitor CVC Asia Pacific's final offer of A$2.00 apiece.

U.S. private equity firm Madison Dearborn already owns more than a 29% stake in the company.

The development comes after private equity firm CVC Asia Pacific failed to finalize its A$1.83 billion ($1.20 billion) takeover offer for APM at the end of a four-week exclusivity period.

CVC had

sweetened

its offer to A$2.00 per share after APM rejected the private equity firm's initial A$1.60 apiece offer saying that the bid did not "sufficiently reflect its fundamental value".

($1 = 1.5218 Australian dollars)