LOS ANGELES (AFP) - Forty-nine year-old Iron Man star Robert Downey Jr has welcomed a second child with his wife Susan, a baby girl named Avri, he announced Wednesday.

"After 9 months of intensive development, Team Downey is pleased to announce our 2014 fall/winter project," the A-list star joked on his Facebook page, adding that she was born early on Tuesday.

"Principal photography commenced 11-14 and will continue until she says, 'Dad! You are embarrassing me... I'm 30, this has gotta stop,'" the veteran actor added.

"Her full name is Avri Roel Downey, she weighs seven pounds, spans 20 inches and "is accompanied by a variety of Susan's traits that have seemingly overwritten my 'junk DNA,'" he wrote.

"I'll post pics here + there when I'm not too busy staring," Downey Jr quipped.

The new arrival is the couple's second child, joining two-year-old Exton Elias.

Downey Jr also has a 21-year-old son, Indio, from a previous marriage.

Downey Jr, Hollywood's highest-paid actor, is currently starring in The Judge, in which he plays a lawyer who returns to his hometown to lay his mother to rest but also to bury the hatchet with his father.

He is due to reprise his Iron Man role in next year's blockbuster Marvel sequel Avengers: Age Of Ultron.