I was with a GE sub from 2003-2006, when it was acquired. Their pension started at age 60 whether you wanted it to or not, an older employee who was still working past age 60 told me she'd looked into that, and found that there was no financial advantage to delaying it, so she was collecting it. I never looked it up but I'm sure it was in the Benefits section of the company Intranet.
I'm still not sure why I was vested in it since I'd worked just shy of 5 years by most definitions (7 months in 2003, which may have been enough to qualify, and 6.5 months in 2006 before the acquisition, plus all of 2004 and 2005). I was 53 at the time of the acquisition so maybe different vesting rules applied to older employees affected by an acquisition. All I know is, I get $933 on the first of every month like clockwork.
My Prudential pension, OTOH, would be $750/month if I took it now and $1,000/month at age 65,so I'm waiting on that one.