Monoline

A business that focuses on operating in one specific financial area. The main advantage of this structure is that these companies have specialized skills and provide expertise beyond what can usually be expected.

For example, monoline insurers give investors and issuers the confidence to participate in the market by providing liquidity and financial protection. Without fully understanding the entire system and how it all comes together, a company is unable to provide its customers with quality service. Due to the expertise that monoline companies have in the industry, they are able to reduce operating cost, enhance customer service and evaluate/manage risk much more efficiently.

Source: Google search (source wasn't recorded at time of reading)