PNC, according to Reuters the 10th-largest US bank, said earlier today it will buy multifamily mortgage originator and servicer ARCS Commericial Mortgage.

Calabasas Hills, California,-based ARCS makes loans that fund purchases of apartment buildings, condominiums and co-ops with at least five units, PNC said. ARCS has 10 loan offices, made more than $2.1 billion of loans in 2006, and services about $13 billion of loans. PNC said. Founded in 1995, ARCS said it employs more than 170 people.

This is a scale purchase for PNC, and gives it a much larger stake in agency-backed multifamily paper.