as it happens

as it happensを「そう言えば」と訳せる例があるに違いないとかねがね思っているのですが、実際に「訳した」例は見つかっていません。

OALDの次の意味記述の最後のところ、something connected to what somebody else has just saidというのは「そう言えば」に近いと思うのですが。

as it happens / happened

used when you say sth that is surprising, or sth connected with what sb else has just said:

• • I agree with you, as it happens.
  • As it happens, I have a spare set of keys in my office.