The Supreme Court said Tuesday it will rule on two cases involving electricity contracts that a Nevada power company and a county in Washington state seek to invalidate because they were signed at the height of the 2000-2001 Western energy crisis.

At issue is the standard used by the Federal Energy Regulatory Commission in a 2003 decision that upheld the contracts, which were signed with subsidiaries of American Electric Power Co. Inc. and Morgan Stanley, among others. Morgan Stanley Capital Group is engaged in energy trading.