WASHINGTON – The number of homeowners dropping out of the Obama administration’s main mortgage assistance plan is growing, and is now almost equal to the number who have received permanent relief.

More than 299,000 homeowners had received permanent loan modifications as of April, the Treasury Department said Monday. That’s about 25 percent of the 1.2 million who started the program since its March 2009 launch. They are paying, on average, $516 less each month.

However, the number of people who started the process but failed to get their mortgages permanently modified rose dramatically in April.

To finish the program, borrowers must make at least three payments on time. About 277,000 homeowners, or 23 percent of those enrolled, have dropped out during this trial phase — up from about 155,000 a month earlier.

Many borrowers are still caught up in a bewildering bureaucracy, housing advocates say.

Most analysts say the administration’s program has yet to make a dent in the foreclosure crisis. But officials insist the program is helping the housing market turn around.