European Union regulators on Wednesday dropped an antitrust investigation into U.S. memory chip company Rambus Inc. after the company pledged to cap royalty fees for its patents on computer memory chips.

Rambus, based in Los Altos, Calif., will avoid any EU fines by pledging not to charge any royalties for SDR and DDR chip standards and to bring fees for newer versions of DDR down from 3.5 percent to 1.5 percent.