Italian has essere / stare.
Irish* and to a lesser extent Welsh also have a split within the verb to be which is very similar but not quite the same as Spanish (or Portuguese). The third-person singular in Irish is tá, cognate with estar (specifically está), and is, pron. “iss”, cognate with ser (specifically es as well as English is). Welsh has the lexical cognates taw and ys*** but functionally the equivalents are mae and yw.****
Not, of course, a Romance language, but arguably is the next closest thing if you believe in Italo-Celtic.*
**The hypothesis that the Romance and Celtic languages are closer to each other than either is to any other branch of Indo-European, i.e. that the split between the Italic group (Latin and a few other languages) and the Celtic languages was chronologically the last node on the tree before Proto-Italic. I buy it, but it’s not exactly universally accepted.
***I’m pretty sure. I didn’t look it up to verify that they’re cognates, though.
****Sort of. All of these are 3rd-person singular forms of “to be”, but there are more (e.g. sy) and it’s even more off-topic.