  A chiral invariant Lagrangian describing the tetraquark-quarkonia interaction
is considered at the leading and subleading order in the large-$N_{c}$
expansion. Spontaneous chiral symmetry breaking generates mixing of scalar
tetraquark and quarkonia states and non-vanishing tetraquark condensates. In
particular, the mixing strength is related to the decay strengths of tetraquark
states into pseudoscalar mesons. The results show that scalar states below 1
GeV are mainly four-quark states and the scalars between 1 and 2 GeV
quark-antiquark states, probably mixed with the scalar glueball in the
isoscalar sector.
