Spell-Like Ability Query

[Ruethgar]

Is there a feat or class feature that allows you to convert spell-like abilities to spell slots/points of equal value? I found one in AEG, but I was wondering if there was one in officially released content, preferably 3.5 but 3.0 is fine.

[Arbane]

Is there a feat or class feature that allows you to convert spell-like abilities to spell slots/points of equal value? I found one in AEG, but I was wondering if there was one in officially released content, preferably 3.5 but 3.0 is fine.

In D&D 3.5, the Archmage prestige class lets you trade spell slots for a spell-like ability.

In PF, witches can get the Spell Hex feat, which turns a first-level spell into a (Sp) hex.

[Ruethgar]

I was looking for the other way around. The AEG one is dragons only, a Black Dragon could give up its Darkness 3/day (Sp) for three second level sorcerer spell slots.