Insurance broker Aon to buy rival Willis Towers Watson for nearly $30 billion

• Aon first approached Ireland-based Willis about a merger last spring, but those talks fizzled and Irish regulations prevented the two sides from striking a new deal until this month.

The bottom line: "Insurance brokerages help companies buy insurance and advise companies on risk management, but are consolidating at a rapid rate following years of sluggish commercial-insurance pricing growth, writes the Wall Street Journal.

Go deeper: Health insurers are eating higher medical costs