list price will be minimum $4

This is in order to satisfy Nasdaq.

Also:

"each ordinary share of Biota capital stock will be exchanged for newly issued shares of Nabi common stock, and Biota will become a wholly-owned subsidiary of Nabi (the "Transaction"). Existing shares of Nabi common stock outstanding at the completion of the Transaction will remain outstanding. In connection with the Transaction, Nabi will change its name to "Biota Pharmaceuticals, Inc." but will remain listed on the NASDAQ Stock Market and headquartered in the U.S....

... The increase in the authorized shares to 200 million is a closing condition to the Transaction and is necessary for Nabi to have sufficient authorized but unissued and unreserved shares of Nabi common stock available for issuance to the stockholders of Biota in the Transaction. The reverse stock split may also be necessary to have a sufficient authorized but unissued and unreserved shares of Nabi common stock available for issuance to the stockholders of Biota in the Transaction.In addition, the proposed reverse stock split is necessary to ensure that the per share price of the common stock of the combined company following the Transaction complies with the NASDAQ's initial listing standards. In accordance with those listing standards, the combinedcompany will be required to have a minimum bid price of the combined company's common stock of at least $4.00 upon the completion of the Transaction...."

See
http://biz.yahoo.com/e/121012/nabi8-k.html