Short plan year (Merged Plan), Extension allowed?

[Guest DonJones]

I haven't been able to find this issue directly addressed by either IRS or DOL documentation, so figured I'd try here. I am wondering if a plan with a short plan year (plan was merged into another plan) is eligible to file a 5558 to extend the 5500 filing deadline 2.5 months after the normal due date. There is nothing in the 5558 instructions indicating this wouldn't be possible, but I've heard murmurs that it isn't allowed. This particular plan has a 3/31/07 year end thus an initial 10/31/07 filing deadline, and the potential extension would be to mid January 2008.

[WDIK]

The 2006 Form 5500 instructions use language that indicate a 2-1/2 month extension can be obtained by filing Form 5558 "on or before the normal due date". The issue of a short-plan year is not specifically addressed, but I would comfortably rely on the extension.