ついては
就いては
tsuitewa

Conjunction

1. in line with this; therefore; consequently; so; such being the case; in that regard; in this connection

Usually Written in Kana
ついては、私わたくし手紙てがみのコピーを添付てんぷいたします。
tsuitewa watashino tegamino kopiio tempu itashimasu
I am sending a copy of my letter to you.