Vanguard, a powerhouse in investment management, announced Wednesday that it will offer a bundled 401(k) plan service for small companies. The service will launch in fourth quarter and is designed for 401(k) and profit-sharing plans with assets below $20 million.

The firm says the new option "combines Vanguard's low-cost investment options and indexing expertise with the small-plans recordkeeping expertise of Ascensus, a leading recordkeeper and administrator of retirement plans."

The retirement plan service will include funds, recordkeeping, call center services, compliance testing, participant education, and optional services such as participant advice, self-directed brokerage, and trustee services. The firm is touting "all-in" plan costs — total investment and recordkeeping costs — anticipated to be among the lowest in the industry.