Andrew Fastow, the mastermind behind financial schemes that doomed Enron Corp., returned to Houston this week to serve the remainder of his six-year sentence at a halfway house, a federal prison official said Wednesday.

Fastow, 49, joined another former Enron executive who is also serving part of his sentence at the halfway house. A third ex-Enron executive who had also been at the halfway house left a day after Fastow arrived, said Chris Burke, a spokesman for the U.S. Bureau of Prisons.

On Monday, Fastow left a federal prison in Pollock, La., where he had served most of his prison sentence, and later that day he reported to the halfway house.

Burke said he could not name the halfway house but added there is only one such facility in Houston, located only a few blocks away from Minute Maid Park, the downtown ballpark of the Houston Astros that was originally named Enron Field.

Attorneys for Fastow did not immediately return telephone calls seeking comment.

Fastow's wife, Lea Weingarten, and the couple's two sons still live in Houston. Weingarten, who served a year in prison for helping her husband hide ill-gotten income from his Enron schemes, now works as an art adviser and curator. She did not immediately return a telephone call or email seeking comment.

Enron, once the nation's seventh-largest company, crumbled into bankruptcy in December 2001 after years of accounting tricks could no longer hide billions in debt or make failing ventures appear profitable. The collapse wiped out thousands of jobs, more than $60 billion in market value and more than $2 billion in pension plans.