Heavy equipment company Caterpillar Inc. said Wednesday that it reached an agreement with mining company BHP Billiton Ltd. to develop an autonomous mining haulage system.

BHP Billiton, the world's biggest miner, reported strong quarterly production gains on Wednesday led by copper and iron ore, but warned of a looming decline from the world's biggest copper mine.

The European Commission opened an in-depth investigation on Friday into BHP Billiton's $170 billion unsolicited bid for rival miner Rio Tinto, with prices of iron ore already soaring.

Australia will increase its scrutiny of foreign investments in Australian mining companies, Treasurer Wayne Swan said on Friday, particularly when the investor is also a major customer seeking a majority stake.

Steel magnate Lakshmi Mittal considered buying a stake in bid target Rio Tinto to expand his interests in iron ore but has decided against it for now, sources familiar with the matter said on Monday.

The resource sector is still the smart investment now, while those attracted to beaten-down financial stocks should proceed with care, analysts told CNBC Europe.

Miner BHP Billiton may be forced to scrap its plan to rewrite the way billions of dollars of iron ore are sold every year after rival Rio Tinto struck a benchmark deal with China, analysts said on Tuesday.

China's state-owned aluminum giant Chinalco is keen to buy a range of global resource assets, and may consider raising its stake in global miner Rio Tinto, the Australian newspaper said on Tuesday.

Production at global miner Rio Tinto will increase as global demand for commodities continues to soar, while prices are likely to continue rising, the company's CFO Guy Elliott told "Squawk Box Europe" on Thursday.

European stocks fell 1.7 percent on Friday, losing ground for the third time in four sessions as a dip in metal prices prompted investors to book recent lofty gains on mining shares.

ArcelorMittal, the world's top steel maker, is in talks with Australia's Macarthur Coal after buying a 15 percent stake in the company, setting up a possible bidding war for the A$4.4 billion group and pushing its shares up 14 percent.

Chinese interests have approached a major Australian superannuation and investment fund to be their partner in a multi-billion-dollar swoop on 9 percent of BHP Billiton, The Australian newspaper reported.

The drugmaker Merck & Co. says its profit almost doubled in the first quarter due to a $1.4 billion distribution from a partner drug company. It sales were slightly higher.

Bank of America Corp. said Monday its profit fell 77 percent in the first quarter, hurt by trading losses and a $3.3 billion increase in reserves for problem loans.

United Technologies Corp. said Thursday its first-quarter earnings rose 26 percent as the weak dollar boosted profits throughout the business.