WASHINGTON - The Securities and Exchange Commission will adopt a new policy on subpoenaing journalists, SEC Chairman Christopher Cox said Thursday in a move to resolve a controversy over the agency's recent demands for reporters' records. Cox and the other four SEC commissioners decided unanimously at a closed-door meeting to issue "clear principles" to guide agency attorneys on media subpoenas within the next week or so, he told reporters in a meeting. On Monday, after news reports had appeared on the matter, Cox took the unusual step of halting the agency's pursuit of subpoenas previously served on columnists for...