Basell North America Inc., Wilmington, Del., added the John Hancock Small-Cap Equity Fund as an investment option in its $295 million 401(k) plan, said Deborah A. Wersinger, manager-compensation and benefits. The change was made because the plans previous small-cap option had become a small-cap to midcap fund. The plan now has 11 options. ADP Retirement Services is record keeper; Chase Manhattan Bank is custodian and trustee. Administration is handled internally.