(adds number of rejected offers, share price, analyst comment)
PRAGUE, July 7 Billionaire Petr Kellner's PPF Group raised its stake in phone operator O2 Czech Republic by 7.16 percent of the stock to 73.1 percent in a mandatory buyout offer to minority shareholders, PPF said on Monday.
The Czech financial group said it has received acceptance notices totalling 16.10 percent of shares, but it rejected 8.9 percent of those due to what it said were "formal shortcomings", PPF said, without elaborating.
PPF had acquired a 65.9 percent stake in O2 Czech Republic from Spain's Telefonica in January and launched a mandatory buyout offer at a price of 295.15 crowns per share in May, which expired last week.
O2 shares were down by 1.1 percent at 265.1 crowns at 1039 GMT, slightly above the day's low of 264.3 crowns. Analysts said that the rejected offers could push the shares slightly down.
"The rejection rate is surprising for us. It will be interesting to see what the rejected investors will do next. We can imagine slight selling pressure triggered by those who wanted to take part in the offer," analysts at J&T Bank said in a note.
They said the result raised the probability of O2 shares staying at the Prague Stock Exchange rather than being delisted. (Reporting by Robert Muller; Editing by David Holmes and Louise Heavens)