Simon Property Group Inc.’s board is working on a long-term employment agreement with Chairman and CEO David Simon, whose compensation rose more than fivefold last year.

Simon received $24.6 million in compensation in 2010, the biggest part of which were stock awards that totaled $19.5 million, according to the biggest U.S. mall owner’s proxy statement filed Friday. The CEO’s total compensation was $4.6 million in 2009.

The compensation committee of Indianapolis-based Simon Property’s board is attempting to structure a long-term deal to keep Simon as leader of the company “for a substantial period of time,” according to the proxy statement. The proxy indicated Simon hasn’t been paid enough.

“The committee has considered for several years that David Simon’s compensation has not been commensurate with his contributions to our success and creation of long-term stockholder value,” the company said in the filing. “The committee is aware that David Simon’s compensation has been significantly less than the compensation of chief executives of many private and publicly held real estate companies as well as non-real estate companies of comparable size and complexity, many of which have not performed as well as we have.”

Simon, 49, son of the company’s co-founder, the late Melvin Simon, has been CEO since 1995 and chairman since 2007. Simon Property shares gained 25 percent last year as revenue rose 4.8 percent, to $3.96 billion. The share increase was in line with the Bloomberg REIT Index.

The company’s market value was $59 billion in 2010, compared with $48.8 billion in 2006, according to the proxy.

Simon Property ended its pursuit of rival General Growth Properties Inc., the second-biggest U.S. mall owner, last year after being rebuffed by the Chicago-based company. General Growth, in bankruptcy at the time, favored a rival proposal to keep it independent and proceeded with that deal.

Simon Property bought Prime Outlets Acquisition Co. in August for $2.3 billion to expand its outlet-mall business.

The company abandoned a takeover pursuit of Capital Shopping Centres Group Plc in January after the London-based company declined to share due-diligence information. Purchasing Capital Shopping would have enabled Simon to enter the U.K., Europe’s largest economy outside the euro region.

Simon Property fell 43 cents Friday morning, to $105.94 each. The shares were up 7 percent this year through yesterday.