COMPAGNIE EBN BATOTA
Go there and contact
It offers daily departures for Benghazi (15 DL, stops in Khoms, Misratha, Syrte, Ben, Ras Lanouf, Ajdabiya), Ghadamès (15 DL, stops at Al-, Kabaw, Nalout, Derj) and Sebha (15 DL, a stop in Shwayrif).
Also some buses for Aman and for Damascus, at 120 DL, and $ 33 for the boat (think more about it anyway). All these buses depart from the Place My'mun in the street of the same name, opposite the company's office. The atmosphere is much less relaxing than at the Dahra bus station: The My'mun street s with minibus, drivers, travellers, traders…
In any case, don't expect brand new and comfortable buses. Beware, stops at different points of check on routes can delay buses by about half an hour or more. The time taken by these controls - mainly aimed at filtering African immigration to Tripoli - will be even longer for returns from southern cities, including Ghadamès.