The board of Apollo Education Group Inc. (Nasdaq: APOL), owner of the University of Phoenix, has approved an increased takeover offer from a group led by Apollo Global Management LLC (NYSE: APO), according to a regulatory filing.

Apollo Global and investors including The Vistria Group LLC raised their bid on May 1 to $10 a share, or $1.14 billion, after some shareholders rallied to block their initial offer. That’s 52 percent more than the Jan. 8 closing price, the last trading day before the company’s board announced it would explore strategic alternatives.

"This increased price per share is now an even better deal for shareholders," states a letter to shareholders from Apollo Education’s board filed Monday with the U.S. Securities and Exchange Commission.

The Apollo Global consortium agreed to buy the education company in February for about $9.50 per share. The group has indicated the new bid is their “best and final offer,” Phoenix, Arizona-based Apollo Education said in the letter.

Investors including Alberta Investment Management Corp. and Schroders Plc sought to halt the earlier deal on the grounds it undervalued the company. They had urged shareholders to reject the purchase in a vote at a meeting scheduled for last week. The meeting was adjourned to May 6, when investors will vote on the revised terms.

A representative for Apollo Global said the company couldn’t immediately comment.

“The merger now provides even greater immediate, certain and fair value to shareholders and, if approved and completed, will eliminate the considerable downside risk facing the shareholders,” Apollo Education said in a statement today.

Apollo Education’s board sent a letter to investors last week stating that it would consider selling the company’s struggling University of Phoenix arm if investors rejected its deal with the buyout consortium.