pipelines
UPDATE 4-SEC steps up probe of Chesapeake, CEO McClendon
* Shares close 2.4 percent lower
(Adds closing share price, company comment)
Rio Tinto and Mongolia mine talks falter
Oyu Tolgoi starts temporary budget to avoid halting operations as talks continue over issues including management fees, cost overruns and transparency
WRAPUP 1-Syrian opposn chief under fire for talks with Assad allies
* Opposition leader met Russian, Iranian and U.S. officials
