WASHINGTON, June 11 (Reuters) - Four more U.S. states on

Tuesday joined the Justice Department's lawsuit against Apple

Inc ( AAPL ) alleging the iPhone maker is monopolizing

smartphone markets, the department said in a statement.

The four states are Indiana, Massachusetts, Nevada and

Washington, the Justice Department said. The original lawsuit

was filed in March, and 15 states and the District of Columbia

joined the lawsuit at the time.

The lawsuit alleges that Apple ( AAPL ) uses its market power to get

more money from consumers, developers, content creators,

artists, publishers, small businesses and merchants. The civil

lawsuit accuses Apple ( AAPL ) of an illegal monopoly on smartphones,

maintained by imposing contractual restrictions on, and

withholding critical access from, developers.

The Justice Department has previously said Apple ( AAPL ) charges

as much as $1,599 for an iPhone and makes a larger profit than

any rival. Officials also said Apple ( AAPL ) imposes hidden charges on

various business partners - from software developers to credit

card companies and even rivals such as Alphabet's,

Google, in ways that ultimately raise prices for consumers.

Apple ( AAPL ) has said it plans to ask a federal judge in New

Jersey to

throw the case out

, arguing that it "faces fierce competition from

well-established rivals."

A spokesperson for Apple ( AAPL ) did not immediately reply to a

request for comment.