WASHINGTON — Evan Bayh, a former Indiana Democratic senator running to get his old seat back, earned nearly $6.3 million since the beginning of 2015, with about a third of the total coming from a private equity fund that hired him shortly after he left Congress, according to financial disclosure records.

The records, filed late Sunday, also show Bayh and his wife have assets worth between roughly $14 million and $48 million.

Bayh served in the Senate from 1999 to 2011. How Bayh spent his time since leaving the Senate has become a major issue in his campaign against Republican Rep. Todd Young for the Indiana Senate seat being vacated by Republican Dan Coats.

The Associated Press reported Saturday that during his final year as a senator Bayh had more than four dozen meetings and telephone calls with headhunters and future corporate employers.

Bayh reported income of just over $2 million from Apollo Global Management, a self-described alternative investment manager based in New York, and $1.9 million from McGuire Woods, an international law firm with a large office in Richmond, Virginia. Bayh earned another $440,000 as a Fox News contributor during the 21-month period, according to the records.

In June 2010, just months before retiring from the Senate, Bayh was among a small group of Democrats who helped kill a tax increase on private equity gains known as carried interest that was opposed by Apollo. That fall he stayed overnight three times at one Apollo executive’s Central Park South residence in Manhattan, and met twice with the company’s chief executive, Leon Black.

Apollo announced Bayh had been hired as a senior adviser weeks after he left the Senate.

The financial disclosure records also show income of $600,000 from the Marathon Petroleum Company. In May 2010, Bayh lunched with a Marathon Oil board member. Then in June, he and a minority of Democrats joined with Republicans to defeat an amendment by Sen. Bernie Sanders, I-Vt., that would have eliminated billions in tax deductions and exemptions for oil and gas companies.

Marathon Petroleum Corp., a new Marathon spinoff, announced Bayh had been elected to its board in July 2011.

Ben Ray, a spokesman for Bayh, said the senator actually supported taxing oil and gas companies as well as taxing carried interest in other votes. But in both cases, the provisions were included in larger pieces of legislation that wasn’t paid for and would add to the national debt.

“Evan Bayh is a fiscally conservative Democrat who was not alone in his caucus in voting against the bills,” Ray said.

Bayh earned an additional $1.16 million since January 2015 by serving as a member of the boards of Berry Plastics Group in Evansville, Indiana; RLJ Lodging Trust in Bethesda, Maryland, and Fifth Third Bank in Cincinnati, Ohio.

Bayh’s job searching before leaving the Senate may have been perfectly allowable under the Senate’s self-policing rules.

A 2007 law requires senators to file a disclosure with the secretary of the Senate within three days of beginning negotiations for private-sector employment. But after the law went into effect, the Senate Ethics Committee defined negotiations as employment discussions that occur after a job offer has been made.

So Bayh would not have had to disclose his job meetings to anyone, as long as they occurred before a solid offer. And because he never filed a disclosure form, Bayh never triggered a related requirement to withdraw from official matters that might have constituted a conflict of interest.

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