Converting SSH2 RSA Private Key to .pem using openssl

When i try to convert SSH2 RSA format based private key to .pem format, using openssl i am getting the below error.

[jbadmin@xxxxxxx .ssh2]$ openssl req -x509 -key /home/jbadmin/.ssh2/id_rsa_2048_a -nodes -days 365 -newkey rsa:2048 -out id_rsa_2048_a.pem
unable to load Private Key
139994671441736:error:0906D06C:PEM routines:PEM_read_bio:no start line:pem_lib.c:703:Expecting: ANY PRIVATE KEY

My Private Key:

[jbadmin@xxxxxx.ssh2]$ cat id_rsa_2048_a
---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----
Subject: jbadmin
Comment: "2048-bit rsa, jbadmin@x01bicallapp1a, Tue Dec 29 2015 11:38:\
----------------------------
----------------------------
---- END SSH2 ENCRYPTED PRIVATE KEY ----

Please suggest me if there is any other way of doing it using openssl or ssh-keygen-g3

EDIT1: Tried below option, still same issue

[jbadmin@x01bicallapp1a .ssh2]$ openssl rsa -outform PEM -in /home/jbadmin/.ssh2/id_rsa_2048_a -out /home/jbadmin/.ssh2/id_rsa_2048_a.pem
unable to load Private Key
140493432293192:error:0906D06C:PEM routines:PEM_read_bio:no start line:pem_lib.c:703:Expecting: ANY PRIVATE KEY

Asked by user149886 (61 )
Jan 04, 2016 at 04:54