UPDATE 1-Berkshire Hathaway has 5.224 pct Munich Re stake

+ Buffett's stake rises to 5.224 percent, including options

+ Options expiry date is March 11, 2010

+ Munich Re shares up 0.3 percent, lag index

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FRANKFURT, Feb 1 (Reuters) - Warren Buffett continued to raise his voting stake in Munich Re and could hold 5.224 percent of the world's biggest reinsurer, including options.

Buffett's Berkshire Hathaway Inc raised the stake it holds directly or indirectly in the reinsurer to 3.278 percent as of Jan. 22, Munich Re said in a statement on Monday.

The stake, which analysts see as probably purely financial rather than strategic, had previously stood at 3.084 percent as of Jan. 19.

Buffett, whose Berkshire Hathaway unit is the third biggest reinsurer in the world, also could hold a 1.945 percent stake in Munich Re through options that are due to expire on March 11.

He also holds a 3 percent stake in the world's second biggest reinsurer Swiss Re.

Munich Re's share has risen by 0.5 percent in the last two weeks and was trading up 0.3 percent at 108.80 euros by 1437 GMT, lagging a 0.7 percent rise in the DJ Stoxx European insurance index.

REUTERS