Contraction.—If either of the syllables to be contracted had an accent, the contracted syllable has an accent. Thus:
a. A contracted antepenult has the acute: φιλεόμενος φιλούμενος.
b. A contracted penult has the circumflex when the ultima is short; the acute, when the ultima is long: φιλέουσι φιλοῦσι, φιλεόντων φιλούντων.
c. A contracted ultima has the acute when the uncontracted form was oxytone: ἑσταώς ἑστώς; otherwise, the circumflex: φιλέω φιλῶ.
N. 1.—A contracted syllable has the circumflex only when, in the uncontracted form, an acute was
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].