UPDATE 1-Czech PPF raises stake in drug maker Zentiva

* PPF raises Zentiva stake to 24.3 pct * Awaiting results of Sanofi-Aventis bid

(Adds details, background)

PRAGUE Oct 23 (Reuters) - Czech investment holding company PPF Group raised its stake in generic drug maker Zentiva ZNTVsp.PR as it awaits the conclusion of a $1.7 billion takeover bid by France's Sanofi-Aventis (SASY.PA), it said on Thursday.

PPF, controlled by tycoon Petr Kellner, increased the percentage of voting rights it controls to 24.26 percent from 21.59 percent, it said in a filing with the Dutch market regulator.

The stake is controlled jointly with Italian insurer Generali (GASI.MI).

A PPF spokesman declined to comment further.

Zentiva is subject of a 1,150 crown per share takeover bid from its largest shareholder Sanofi-Aventis, which has a 24.9 percent stake. The bid values the Czech company at 43.86 billion crowns.

PPF launched a 950 crown per share takeover bid for Zentiva in May when it held 19.2 percent in the company but withdrew it after Sanofi counterbid 1,050 crowns.

Belviport Trading Ltd, a closely held firm whose owners remain anonymous, declared its shareholding in Zentiva in September, later raising its stake to just above 10 percent.

Czech media reported Belviport belonged to billionaire Pavel Tykac who may have joint plans with PPF's Kellner.

PPF denied acting in concert with Belviport. (Reporting by Jana Mlcochova; Editing by Hans Peters)