Oil slips below $126 per barrel: Oil dropped below $126 on Friday after a regulatory probe into possible price manipulation added to trader caution and a stronger US dollar offset the impact of a big drop in US crude stocks. US crude dipped 77 cents to $125.85 a barrel by 1030 GMT. London Brent dropp ed 49 cents to $126.40. Prices hit an all-time high of $135.09 a barrel last week, driven by concern supplies will struggle to match demand over the long term, as well as a weak US currency, which makes dollar-denominated commodities attractive to investors. Since then, the market has fallen by around $10, pulled lower by mounting evidence that in the short term high prices have begun to erode demand. An announcement on Thursday of an investigation by US regulator the Commodity Futures Trading Commission (CFTC) heightened the cautious mood. "A rebound in the dollar, speculation about US interest rate hikes and the announcement by the CFTC of measures to enhance the oversight of energy...