A leading lawmaker on privacy issues said on Thursday he would ask for a probe into whether recently announced changes in how Google handles consumer data violated an agreement it made with the U.S. Federal Trade Commission.

Representative Edward Markey was also one of eight U.S. lawmakers who sent a letter to Google expressing concern that a planned consolidation of user information may make it more difficult for consumers to protect their privacy.

In a separate statement, Markey went further: I plan to ask the Federal Trade Commission whether Google's planned changes to its privacy policy violate Google's recent settlement with the agency.

Following a messy rollout of Google's now defunct social network Buzz, Google and the FTC reached a settlement in March last year that requires consent if Google collects information under one privacy policy but then changes that policy.

Google, whose offerings include its flagship search product, Gmail, YouTube and Google+ products, announced on Tuesday that it was unifying 60 of its privacy policies. The company said it would mean a simpler, more intuitive Google experience.

However, after the new policy comes into effect, user information from most Google products will be treated as a single trove of data, which the company could use for its targeted advertising dollars.

The lawmakers said the announcement raises questions about whether consumers will have enough power to opt-out of data sharing systems. They also asked what security steps are being taken to ensure the safety of customer data.

While Google suggests that the purpose of this shift in policy is to make the consumer experience simpler, we want to make sure it does not make protecting consumer privacy more complicated, the lawmakers said in a letter to Google Chief Executive Larry Page.

The letter was dated Thursday.

Republican signatories were representatives Cliff Stearns, Joe Barton and Marsha Blackburn.

Democratic signatories were representatives Markey, Henry Waxman, Dianne DeGette, G.K. Butterfield, and Jackie Speier, who has introduced privacy legislation.

All of the lawmakers except for Speier are members of the Energy and Commerce Committee.

Google, in a statement from policy manager Betsy Masiello, insisted on Thursday that users had choice and control.

We're not collecting more data about you. Our new policy simply makes it clear that we use data to refine and improve your experience on Google, she wrote. We're making things simpler and we're trying to be upfront about it. Period.

Online privacy has come under scrutiny from Washington as a handful of web giants have been accused of compromising user privacy to attract advertisers.

Late last year, Facebook settled with the FTC agreeing to be regulated for a period of 20 years whenever it decides to change its privacy policy.

In 2010, the FTC settled charges with Twitter, after the agency alleged that the social networking service had failed to safeguard users' personal information.

U.S. regulators are reportedly looking into whether Google manipulates its search results to favor its own products and have expanded the probe to include Google+.

(Reporting By Diane Bartz in Washington and Lisa Richwine in Los Angeles; Editing by Tim Dobbyn)