BUENOS AIRES, Oct 2 (Reuters) - Argentine stocks rose on Tuesday after the world's largest steel group ArcelorMittal ISPA.AS said it planned to buy the rest of the Argentine steelmaker Acindar ACI.BA, which it already controls.
The benchmark MerVal .MERV index rose 1.3 percent to close at 2,260.45 points, led by Acindar's gain of 13 percent to 5.44 pesos per share.
"The MerVal was driven up once rumors about Acindar were confirmed," said Diego Zabaleta, a trader with the Besfamiglie brokerage.
"(But) beyond the stock market jump, this is bad news because we'll lose one of the stocks that has historically been popular on the market," he added.
ArcelorMittal offered 1.83 dollars per share for the remaining 34.7 percent of Acindar's stock, a value 19.5 percent greater than the trading price at the close of trade on Monday. It currently holds a 65.3 percent stake.
"This is good news for those who hold the company's stock, but bad for the market in general since there exists the possibility that one of the most popular stocks will move away," said Claudio Szlaien, an analyst with Marlon Financial Resources.
Acindar accounts for 5.02 percent of the MerVal's weighting.
ArcelorMittal's offer also affected trade within the sector, with fellow steelmaker Siderar SID.BA rising 6.69 percent to 24.7 pesos per share and top aluminum producer Aluar ALU.BA up 3.14 at 6.57 pesos per share.
Volume on Argentina's broad market was a heavy 151 million pesos ($47.4 million), of which 32 million pesos corresponded to Acindar trade. Of active issues, 55 advanced, 20 declined and 6 were unchanged.
Bond prices on the local market closed with mixed results as institutional investors reshuffled their portfolios, but rose 0.2 percent on average <AR/BONOS>.
Trade was concentrated in dollar-denominated Par bonds, which rose 1.1 percent, and dollar-denominated Boden 14 bonds, which shed 0.95 percent.
On the foreign exchange market, the peso closed stable amid a slightly heavier flow of dollars.
The peso stayed at 3.1850/3.1875 per U.S. dollar in trade between foreign exchange houses, as measured by Reuters ARSB=.
In interbank trade, where the central bank intervenes almost daily, it firmed 0.08 percent to close at 3.1450/3.1475 pesos per dollar ARS=RASL.