At the end of the rerun of Lupin III: Dead or Alive on Nihon TV on April 29th, a new anime "series" of Lupin III was announced to be aired this autumn. The last TV series aired in the 1980s.

MyCom Journal and Mainichi Digital Newspaper reported the new anime but they didn't say it's a series. It's uncertain whether there will be a TV series or a special one-shot. The previous one-shot Lupin III: The Last Job aired in February 2010.

The aging of the cast has been discussed.
Zenigata: Naya Goro, 81 years old
Jigen: Kobayashi Kiyoshi, 78 years old
Fujiko: Masuyama Eiko, 75 years old
Goemon: Inoue Makio, 70 years old
Lupin III: Kurita Kanichi, 53 years old

Sources: Screenshot of the announcement, MyCom Journal

Lupin III: Blood Seal - Eternal Mermaid on MAL