SBC, previously known as Southwestern Bell and later as AT&T, had been lobbying lawmakers in the early 2000s on a range of matters, including a deregulation bill that would allow it to raise rates and a separate regulatory effort to reopen a bribery case from a decade earlier. Mr. Pruitt sided with the company on both matters, state records show.

In 2005, the shell company — Capitol House L.L.C. — sold the property for $95,000 more than it had paid. While shell companies are legal, they often obscure the people who have an interest in them, and none of Mr. Pruitt’s financial disclosure filings in Oklahoma mentioned the company or the proceeds — a potential violation of the state’s ethics rules.

The Oklahoma City deal, which has not been previously reported, was one of several instances in which Mr. Pruitt appeared to have benefited from his relationships with Mr. Kelly and Mr. Wagner while in state politics.

During his eight years as a Republican state senator, Mr. Pruitt also upgraded his family residence in suburban Tulsa from a small ranch-style home to a lakefront property in a gated community. In addition, he bought a sizable stake in a minor league baseball team, and took a second job at Mr. Wagner’s corporate law firm. Mr. Kelly’s bank, SpiritBank, would be there for much of it — providing financing for Mr. Pruitt’s Tulsa home and his stake in the baseball team, as well as the mortgage for the Oklahoma City house.

Mr. Pruitt’s interactions with SBC also show that his blurring of lines with lobbyists has roots in his Oklahoma years. One of the issues at the E.P.A. that has gotten Mr. Pruitt in trouble with government watchdogs involved his renting a room in Washington for $50 a night from the wife of an energy lobbyist who has had business in front of the agency.

Lobbyists and others in Oklahoma state politics who encountered Mr. Pruitt recalled him as a tough competitor who always had his eye on a higher office. Some called him a “Boy Scout” who was stingy with his money, while others said privately that he had exuded a sense of entitlement — that rules did not apply to him.