(Telecompaper) Latin American mobile operator NII Holdings, working under the Nextel brand in Mexico, Brazil, Argentina and Chile, has retained UBS Investment Bank as its financial advisor to explore and advise the company on potential strategic opportunities. These opportunities include creating partnerships or alliances, selling or merging one or more of the company's business units or other strategic transactions involving the entire company. Nextel has also announced it has retained Rothschild as its financial advisor to explore and advise the company regarding opportunities for modifying its capital structure to improve its long-term liquidity position, including potential approaches that could lead to refinancing or restructuring all or a portion of its existing debt obligations.