Private-equity giant Carlyle Group has agreed to pay $20 million and make several reforms to resolve its role in a corruption investigation of the New York state pension fund that has sparked related inquiries nationwide.

Announcing the deal yesterday, New York Attorney General Andrew Cuomo said Carlyle won't face any action in his investigation of alleged improper payments made by private firms to win New York public pension system investments.

The agreement also covers Carlyle's work with other public pension plans nationally, Cuomo said.

The Washington, D.C.-based Carlyle owns Hawaiian Telcom, having acquired the local phone company from Verizon Communications Inc. in 2005 for $1.6 billion.

Under the agreement, Carlyle agreed to adopt a Cuomo-crafted code of conduct designed to bar investment firms from hiring lobbyists, placement agents or others who use political connections to help the firms win lucrative pension fund deals.

The code also bars firms from doing business with public pension funds for two years after making campaign donations to government officials with influence over the funds' investments.

Aimed at stopping pay-to-play schemes, the contribution ban applies to principals of investment firms, as well as their relatives, company agents and employees. It also applies to firms that currently do business with public retirement systems.

Investment firms must also disclose their contributions and any conflicts of interest to public pension fund officials or law enforcement authorities.

Cuomo said the deal would "help eliminate the conflicts of interest and corruption inherent in a system that allows people to buy access to those holding the pension fund purse strings."

He voiced hope that Congress or the Securities and Exchange Commission — which plans to weigh similar restrictions on campaign giving — applies the rules nationally.