Chicago trading firm Peak6 Investments is spinning out its $2.3 billion hedge fund business, which will change its name and focus on growth by trading European credit and stocks out of a new London office.

Peak6 Investments, which specialises in options trading and clearing using its own capital, told investors Thursday of the plans to sell its stake in its Peak6 Advisors hedge fund business, according to a letter sent to hedge fund clients reviewed by The Wall Street Journal.