Private equity firm The Carlyle Group has agreed to pay $20 million to the State of New York and follow a new code of conduct rules for interacting with public pension funds to settle a corruption investigation carried out by the office of New York Attorney General Andrew Cuomo.

The code of conduct prevents firms such as Carlyle from hiring lobbyists known as placement agents, which reach out to public funds, according to a statement released by the Attorney General. The rules will also bar firms from doing business with a public fund which makes campaign contributions to politicians that can influence the fund’s investment decisions. Funds would also be barred from making similar contributions.

The investigation found that Carlyle had limited success in getting investments from the New York State Common Retirement Fund until in 2004 it hired Henry Morris, the chief political aide to state Comptroller Alan Hevesi, as a placement agent.

After winning more than $730 million in investments from the fund, the Attorney General’s office says Carlyle paid Searle & Company, a broker-dealer associated with Morris, nearly $13 million. Searle then paid “the lion’s share” of the placement fees to PB Placement, LLC, a company controlled by Morris, the investigation found.

Carlyle had not known about that Morris had allegedly agreed to split fees in half with hedge fund executive Barrett Wissman. Wissman pleaded guilty to securities fraud in April and is cooperating with Cuomo’s investigation. Morris has been charged by the Attorney General’s office.

Carlyle said it was “pleased” to resolve the matter and “strongly” supported the new conduct rules. Cuomo hopes that the new guidelines will “set a new standard for ethics in the industry.”