Partnership Interest Sale Capital Gain-Offset with Passive Loss?

[James Sun]

One of my investments went full cycle, but the sponsor sold the partnership interest in the properties instead of the property itself.  As a result, the gain is reported on Box 9a (Net long-term capital gain) instead of 10 (Net section 1231 gain). 
The question is whether the capital gain can be offset by passive losses.  The Sponsor company is stating that investors should provide this reference to their accountant -
Passive activities are discussed in Internal Revenue Code Section 469 and its accompanying regulations. Treasury Regulation §1.469-2T specifically addresses the treatment of gain from the disposition of a passive activity.

Anyone have experience with this topic?