** Shares of SML Isuzu SMLI.NS fall as much as 10%, the lower limit of the exchange-allowed trading band, to 1,596.10 rupees
** Indian automaker Mahindra and Mahindra MAHM.NS on Saturday struck a deal to buy majority stake in SML Izusu for 5.55 bln rupees to bolster its truck and bus business
** Purchase price is 650 rupees per share, a 63% discount to SML's closing price of about 1,773.4 rupees on Friday
** Mahindra to also launch a mandatory open offer for an additional stake of up to 26% at 1,554.6 rupees per share
** Co will acquire Sumitomo Corp's 8053.T 43.96% stake and Isuzu Motors' 7202.T 15% stake
** Day's losses trim SMLI's YTD gains so far to 26.5%; MAHM last up 1.1%, cutting YTD losses to 4.8%
(Reporting by Meenakshi Maidas in Bengaluru)
((Meenakshi.maidas@thomsonreuters.com;))