The board of Simon Property Group Inc , the largest owner of U.S. malls and outlet centers, has agreed to a plan that will give CEO and Chairman David Simon 1 million shares for him to remain with the company for at least another eight years, according to a regulatory filing.

Based on the share price when the board entered into the agreement on July 6, the retention award was valued at $120.3 million, according to a filing on Thursday with the Securities and Exchange Commission.

The long-term incentive performance units, which are like shares once they are earned and vested, will be doled out in three stages beginning in year six, according to the filing.

David Simon also is entitled to remain in the long-term incentive performance program, according to the filing. That program awards the top eight executives $35 million under the 2011 program. As chief executive officer, his share is $12 million, according to the filing.

The 2011 program will be based on performance over the years 2011 through 2013.

Simon also gets an annual salary of $1.25 million. But he also is eligible for an annual target cash bonus of 200 percent of his base salary, or another $2.50 million, if he meets certain performance goals, according to the filing.

Simon Property Group is the largest U.S. real estate investment trust. David Simon's became CEO in 1995, when the market capitalization was $1.5 billion, according to the filing. As of July 6, when the board and its Compensation Committee approved the plan, the market capitalization of the Indianapolis-based company was more than $42 billion.

Shares of Simon closed up 1.1 percent or $1.35 at $121.58 on the New York Stock Exchange. Year to date, shares are up 22 percent. (Reporting by Ilaina Jonas; editing by Andre Grenon and Lisa Shumaker)