International stocks trading in New York closed lower on Thursday, with the Bank of New York index of American depositary receipts falling 0.5% to 156.47. The European index dropped 0.5% to 152.53, the Asian index fell 0.5% to 153.56, the Latin American index declined 0.6% to 315.48 and the emerging markets index fell 0.6% to 315.00. Among the companies with shares actively trading were Oi SA (OIBR, OIBR4.BR) and AstraZeneca PLC (AZN, AZN.LN).

Brazilian telephone company Oi will ask local rivals for help in buying and splitting up TIM Participacoes SA (TSU, TIMP3.BR), the Brazilian mobile phone company controlled by Telecom Italia SpA (TI, TIA, TIT.MI), according to The Wall Street Journal, which cited two people familiar with the plans. Oi shares rose 1.7% to 64 cents, while TIM shares fell 3% to $27.30.

AstraZeneca shares rose on speculation that the drug maker will sit down with former suitor Pfizer Inc. (PFE) next week when U.K. takeover rules allow talks to resume. AstraZeneca shares popped nearly 1% to $74.24.

PetroChina Co. (PTR, 0857.HK, 601857.SH, K3OD.SG), China's biggest listed oil company by capacity, said Thursday its first-half net profit rose 4% from a year earlier after its refining business swung to a profit and its chemicals business narrowed its loss. Still, shares fell 2.2% to $142.19.

PetroChina rival Cnooc Ltd. (CEO, 0883.HK) recorded a 2.3% decline in net profit to 33.59 billion yuan for the half on rising operating costs. Shares slipped 1% to $194.51.

The shares of ENI SpA (E, ENI.MI) and Enel SpA (ENEL.MI) won't suffer downward pressure if the Italian government decides to sell a stake in each of the companies, according to Equita Sim. Italian press reports say the government, looking to lower the crippling national debt, will sell 4.3% of oil and gas giant ENI and 5% of Enel, the country's largest utility, by the end of the year. ENI shares still slipped 1.5% to $49.55.

France's Vivendi SA (VIVEF) in a swift decision Thursday favored an offer valued at nearly $10 billion from Spanish telecom giant Telefonica SA (TEF, TEF.MC) for its Brazilian telecommunications unit GVT over that of rival Telecom Italia SpA (TI, TIA, TIT.MI), ending a surprise bidding war between two of Europe's largest telecom companies. Vivendi's decision came just hours after the French media giant received a sweetened bid from Telefonica and a rival bid by Telecom Italia. Telefonica shares edged down 0.9% to $15.84, while Telecom Italia shares edged up 0.4% to $11.40.

French water and waste collection utility Veolia SA (VE, VIE.FR) on Thursday kept its full-year targets after posting a rise in first-half profits and sales helped by growth in markets outside France. Still, shares fell 1.1% to $18.19.

Deutsche Bank AG's (DB, DBK.XE) London branch was fined GBP4.7 million ($7.8 million) on Thursday by the U.K.'s Financial Conduct Authority for putting the wrong buy and sell markets on millions of transactions in regulatory reports. Shares fell 1.9% to $34.40.

Write to Anna Prior at anna.prior@wsj.com