WASHINGTON, Dec 17 (Reuters) - Some of the largest U.S. mpanies will have to file their financial reports next year using technology designed to make it easier for investors to read and analyze the data under a rule adopted by U.S. Securities and Exchange mission on Wednesday.

The SEC voted 4-1 to require 500 of the largest public mpanies to begin filing their financial reports using the technology known as XBRL, or extensible business reporting language, by mid-2009.

The SEC voted, also by 4-1, in favor of requiring mutual funds to file their risk and return information using XBRL to make it easier for investors to analyze the performance, risk and fees of thousands of funds. Mutual funds will be required to file the data using the electronic tags by Jan. 1, 2011.