NEW YORK (Reuters) - Charles Schwab Corp's (>> Charles Schwab Corp) automated investment service grew about 29 percent to $5.3 billion at the end of the fourth-quarter, rising despite volatile U.S. financial markets, a spokeswoman said Wednesday.

Schwab Intelligent Portfolios, a "robo adviser" that allocates cash among exchange-traded funds according to formulas based on client questionnaires, has been boosted by sign-ups from investors since its launch last March.

The San Francisco-based company previously reported the program's total assets stood at $4.1 billion, as of Sept. 30, the spokeswoman, Alison Wertheim, said.

Competition has spread in the digital financial-advice market. Fidelity Investments said in November it is building an automated portfolio-management service for individual investors, called Fidelity Go. BlackRock Inc (>> BlackRock, Inc.), the world's largest money manager with $4.5 trillion under management, announced it would acquire the automated platform FutureAdvisor in August.

Schwab makes Intelligent Portfolios available to clients directly and through the firm's affiliated third-party financial advisers.

(Reporting by Trevor Hunnicutt; Editing by Bill Trott)

By Trevor Hunnicutt

Stocks treated in this article : BlackRock, Inc., Charles Schwab Corp