ABC News' Matthew Jaffe reports: The chief of the government’s $700 billion bailout program announced today that he is resigning from his Treasury Department post. In a letter to staff at Treasury’s Office of Financial Stability, Herb Allison said he will return to Connecticut to spend time with his wife Simin at the end of the month. “With the TARP program entering a new phase and continuing to wind down, I have decided that now it is the right time for me to step down as Assistant Secretary for Financial Stability,” Allison said. The controversial TARP will expire on October 3. In his letter, Allison touted that the program “has proven remarkably successful in achieving its goal of stabilizing the financial sector and laying the foundation for our nation’s economic recovery – at a fraction of the cost that was originally anticipated.” However, bailout watchdogs such as the Congressional Oversight Panel and the Special Inspector General for the TARP have criticized the program for helping Wall Street but not Main Street. Treasury Secretary Tim Geithner has tapped Tim Massad to serve as acting head of the Office of Financial Stability until a permanent replacement for Allison is named. Massad currently serves as chief counsel and chief reporting officer of OFS.