NEW YORK (Reuters) - Women in the United States are paid less for equal work than men in all industries and a new report released on Thursday showed the widest discrepancy in wages is between married men and women with children.

Fathers earned the highest overall median salaries at about $67,900, compared to $46,800 for married mothers, and single women with children had the lowest median salary at $38,200.

"The gender pay gap is absolutely real," said Aubrey Bach, senior editorial manager of PayScale Inc., the online salary, benefits and compensation information company that compiled the report.

"Half or more of our workforce is made of women but we are still not progressing at the same level as men," she added.

While men's salaries kept increasing until the age of 50 to 55, reaching a median salary of $75,000, the report showed women's wages hit a plateau between 35 to 40 years old at about $49,000.

The gender pay gap widened further as the job level increased with male executives earning many times more than their female counterparts.

PayScale calculated the gender pay gap by analyzing data from a poll of 1.4 million full-time employees. It used an algorithm to estimate the controlled median pay for women by adjusting for factors such as experience, education, skills, company size and management responsibility and other factors.

The report found the largest gender pay gaps in the mining, quarrying and gas exploration industries and the smallest in technology jobs, where the ratio of men to women is 70 to 30 percent.

"If a woman can get into the tech industry and stay there it is a kind of a meritocracy," said Bach. "You are going to be paid equally. Unfortunately when you look at the demographic very few women go into the tech industry, especially in technical roles, which are the most highly paid."

In four states, Alaska, Delaware, Michigan and Washington, the most common job for men has a median income higher than $100,000, according to the report, but there are no states in which the common job for women exceeds $77,000.

"A big reason for the gender pay gap is that men and women tend to work in different jobs. Men dominate higher paying jobs, engineering, construction mining, and women dominate jobs like teaching and social work," Bach explained.

Research has shown that women also do not negotiate for salary increases as often or for as much as men and they still face the maternal wall, when companies expect them to leave to care for children, which contributes to the pay gap.

Despite the value of education, the report found it does not solve the problem because the gap was widest among men and women with PhDs, followed by MBA holders.

"Companies in the past haven't linked the return on investment for fostering diverse workforces," said Bach "and they haven't been aware of the really subtle behaviors that are preventing women from getting hired in high-paying roles or rising to executive levels."