French oil companies Total Fina and Elf Aquitaine have agreed to merge in a $54.3 billion deal that would create the world's fourth largest oil group and end a two-month takeover battle. Total is offering 19 of its own shares for 13 Elf shares. The two oil groups had been at a standoff since July, when Total Fina launched an unsolicited 4-for-3 share swap valued at $44 billion for Elf. Elf resisted the hostile offer, coming back with its own $51 billion cash-and-stock counterbid to acquire Total Fina. Elf said today, however, that its offer for Total Fina is ``no longer necessary'' and that both companies would drop legal cases contesting the original bids. Total Fina Chairman Thierry Desmarest will head the new group, while Elf Aquitaine Chairman Philippe Jaffre will step down, the companies said. Total Fina, already the world's fifth-largest oil company, was created in December after Total bought the Belgian refiner Petrofina for $11.8 billion.