Deals of the day -- mergers and acquisitions

Jan 30 (Reuters) - The following bids, mergers, acquisitions and disposals involving European, U.S. and Asian companies were reported by 0530 GMT on Wednesday.

(For Reuters columns on deals, click on [DEALTALK/])

** BHP Billiton Ltd/Plc (BHP.AX)(BLT.L) could afford a 4.25-for-one offer for Rio Tinto Ltd/Plc (RIO.AX)(RIO.L), advisers to Rio have calculated, which would be worth more than $157 billion. To read more, please double click on [nSYD201552]

** Japan's Mitsubishi Materials Corp (5711.T), a nonferrous metal smelter, said it would spend $900 million to lift its stake in U.S. cement firm Robertson's Ready Mix, the latest deal in the M&A heavy sector. [nT149691]

** Indonesian state-controlled mining group PT Antam (ANTM.JK) and Chinese miner Shenzhen Zhongjin Lignan Nonfemet Co Ltd (000060.SZ) launched a joint cash bid of A$504.8 million ($451 million) for Australia's Herald Resources Ltd (HER.AX). [nSYD92229]

** Orica Ltd (ORI.AX), the world's biggest explosives maker, said it had agreed to acquire Strata Control Systems for an undisclosed amount, to boost its exposure to the booming mining sector. [nSYD198774]

** NexCen Brands Inc NEXC.O said it acquired the Great American Cookie Co from Mrs. Fields Famous Brands LLC for $93.7 million to boost the number of brands in its quick service restaurant portfolio. [nWNAS8323]

** Electronic publisher Thomson Corp TOC.NTOC.TO said it has bought income-tax software provider TaxStream for an undisclosed amount. [nWNAS8311]

** Australia's Primary Health Care Ltd (PRY.AX) extended its A$2.7 billion ($2.4 billion) offer for Symbion Health Ltd SYB.AX by two weeks to Feb. 21, while it was talking to a former rival bidder about a possible compromise. [nSYD17558] (Compiled by Tina Kwan in Singapore)