While Berkshire's aggressive expansion in the excess and surplus lines space earlier this year through the hiring of top American International Group employees hasn't significantly altered the market yet, Fitch Ratings says it expects pricing implications related to this expansion "to materialize in coming quarters."

In a recent report on the E&S market, Fitch says the recent strong profit growth over the last several years will moderate going forward, a victim of growing capacity, which limits rate hikes and promotes persistent competition in various excess and surplus lines markets.

The report said the formation of Berkshire Hathaway Specialty Insurance in the second quarter of 2013 "adds tremendous capacity to an already overcapitalized market, which will likely limit rate hikes and lead to more intense competition in 2014."