Professor Millard (1992) has challenged the notion that Yahweh names exist in the Ebla, Ugarit and Mari archives:

"Was the Hebrew God Yahwehc worshipped at Ebla? The claim was made, based on the element ya in names at Ebla. The divine name Yahweh is commonly contained in Hebrew personal names in the form -yah (or -yahuÆ), as in Isaiah, Hezekiah, Michaiah (in English spellings, i replaces y). The divine name also appears as yoÆ or ye-hoÆ in names like Jonathan, Joram or Jehoshaphat (in English, j replaces the y). Pettinato carefully avoided associating the Ya of Ebla with the God of Israel, saying simply that it might be an abbreviation of a name Yaw. Mitchell Dahood, however, contended that this was evidence for a Canaanite deity Ya equated with the name of Israel’s God, found as Yah in some texts.15 This link, however, has been refuted by several Assyriologists.

Why do they disagree? Many personal names at Ebla contain the Sumerian sign NI. Pettinato read NI with the value yà in Semitic. He did so because in some cases this sign (NI) stands in the position taken by a god’s name in parallel forms. Take the name Mikael (English Michael), which means “who is like god [el]?” Here the ending el incorporates the divine element (the god El, also serving as the word for “god”). Later, the name Mi-ka-NI appears. How is the Sumerian sign NI to be read? Pettinato assumed, since it stands in the same place as el, that it too was a divine element, to be read in Semitic as yà (or yah). Thus, he read this name as “Mikaya,” which would then mean “who is like Ya?” But the sign NI, which Pettinato read yà (or ià), also has the values ni, ì and ’a at Ebla, and may be read variously according to the context. As the final part of a name, it marks a shortened form. Thus Mikaya could be short for Mika-El or Mika-Dagan, or similar combinations.

The existence of alternate forms, some with divine name in the final part of a personal name, as in Mika-el:Mika-NI, is not evidence in itself that this final element is a divine name in the latter form. Where NI occurs in other positions it may simply be part of the syllabic spelling of the word. Thus in ìl-NI-ra-mu, the word “god” (il) precedes NI; here NI may simply be the possessive suffix iµ so that the name begins “my god.” (The entire name means “my god is exalted.”)

Nothing else at Ebla points to the existence of a god Ya or Yaw, although divine names can be preserved in proper names alone. Incidentally, evidence supposedly showing that a god Ya existed at Ugarit is equally unsatisfactory. Also unconvincing is the evidence from Amorite names in the Mari tablets. Clearly, the NI sign does not mean ya as divine name.

The origin of the name Yahweh is a continuing scholarly quest. Finding a wholly acceptable explanation of this distinctive feature of Israelite religion would make historians more comfortable, for the unexplained always creates unease, and the biblical claim of a divine revelation to Moses falls outside the historian’s scope. However, Ebla offers no help."

(Alan Millard. "Ebla and the Bible, What’s left (if anything)?" The Biblical Archaeology Review. April 1992)