The pace of existing sales increased for the fourth month in a row in June, according to the National Association of Realtors. The organization says an increase in first-time buyers was a major factor in propelling sales during the month.

The number of existing home sales—defined as completed transactions involving single-family homes, condominiums, townhouses, and co-ops—stood at a seasonally adjusted annual rate of 5.57 million. This was an increase of 1.1 percent from the downwardly revised rate of 5.51 million recorded in May, and a year-over-year increase of 3 percent. June's figure was also the fastest annual pace recorded since the February 2007 rate of 5.79 million.

"Existing sales rose again last month as more traditional buyers and fewer investors were able to close on a home despite many competitive areas with unrelenting supply and demand imbalances," said Lawrence Yun, chief economist at the National Association of Realtors. "Sustained job growth as well as this year's descent in mortgage rates is undoubtedly driving the appetite for home purchases."

Sales to investors dropped to their lowest share since July 2009. Individual investors accounted for 11 percent of June's existing home sales, down from 13 percent in May and 12 percent in June 2015.

Investors are more likely to purchase a home without financing, with 64 percent of these buyers paying cash for a property. All-cash transactions accounted for 22 percent of existing home sales in June, unchanged from both the previous month and previous year.

At the same time, first-time buyers made up a larger share of the market. These buyers accounted for 33 percent of existing home sales in June, up 3 percentage points from both May and June 2015. The share of first-time buyers was at its highest point since July 2012, when 34 percent of existing homes were sold to people who were making their first home purchase.

The share of first-time buyers has been gradually increasing in the past year. On average, these buyers purchased 31 percent of existing homes in the first half of 2016. They accounted for 30 percent of existing home sales in 2015.

"The modest bump in June sales to first-time buyers can be attributed to mortgage rates near all-time lows and perhaps a hopeful indication that more affordable, lower-priced homes are beginning to make their way onto the market," said Yun. "The odds of closing on a home are definitely higher right now for first-time buyers living in metro areas with tamer price growth and greater entry-level supply – particularly areas in the Midwest and South."

Freddie Mac put the average commitment rate for a 30-year fixed rate conventional mortgage at 3.57 percent, down from 3.6 percent in May. This was the fourth consecutive month where the average mortgage rate decreased, reaching its lowest point since the average of 3.54 percent in May 2013. The average mortgage rate in 2015 was 3.85 percent.

At the same time, the trend of shrinking inventory and rising home prices continued in June. There were 2.12 million existing homes for sale in June, down 0.9 percent from May and 5.8 percent from June 2015. The median existing home price in June was $247,700, a 4.8 percent increase from the previous year and the 52nd consecutive month of year-over-year price gains.

"Looking ahead, it's unclear if this current sales pace can further accelerate as record high stock prices, near-record low mortgage rates, and solid job gains face off against a dearth of homes available for sale and lofty home prices that keep advancing," said Yun.

Tom Salomone, president of the National Association of Realtors and a real estate broker in Coral Springs, Florida, said first-time buyers should have an easier time purchasing a condominium due to recent legislation. The U.S. Senate unanimously passed the bipartisan Housing Opportunity Through Modernization Act on July 14, easing some restrictions on financing for condominium purchases.

"At a time of historically low mortgage rates, this is a huge win for prospective first-time and low- to moderate-income buyers interested in purchasing a condo," said Salomone. "Eliminating overly burdensome restrictions on condos will help more of these prospective buyers access financing and take advantage of this affordable entry point into homeownership."

The typical existing home spent 34 days on the market before a sale in June, unchanged from the previous year but up from 32 days in May. Forty-eight percent of existing homes sold in June were listed for less than a month before selling.

Six percent of June's existing home sales were distressed properties such as foreclosures and short sales. This share was the same as in May but down 2 percentage points from the previous years.

Foreclosures made up 4 percent of existing home sales, the lowest share since the National Association of Realtors began tracking this information in October 2008. The average foreclosure sold for 11 percent below its market value in June, down from 12 percent in May. These properties spent a median of 49 days on the market before selling.

Short sales accounted for 2 percent of existing home sales and had an average discount of 18 percent, up from 11 percent in May. These properties were on the market for a median period of 156 days before selling.

The seasonally adjusted annual rate for single-family home sales was 4.92 million, an increase of 0.8 percent from May and 3.1 percent from June 2015. The median price for this type of home was up 5 percent from the previous year to $249,800.

Existing condominium sales increased 3.2 percent from May and 1.6 percent from June 2015 to a seasonally adjusted annual rate of 650,000 units. The median condominium price in June was $231,600, a year-over-year gain of 3.2 percent.

The Northeast was the only region where existing home sales were down from May, dropping 1.3 percent to a seasonally adjusted annual rate of 760,000. However, this pace was 5.6 percent above that of June 2015. The median existing home price in the region was $284,800, a year-over-year increase of 1.4 percent.

The annual rate of 2.26 million existing home sales in the South was unchanged from May, but up 3.2 percent from June 2015. An existing home in this region sold for a median price of $217,400, 5.5 percent more than the previous year.

The West had the strongest year-over-year growth in home value, with the median price for an existing home climbing 7.2 percent to $350,800. The annual rate of existing home sales in June was 1.2 million, up 1.7 percent from the previous month and 0.8 percent from the previous year.

The existing home sales in the Midwest had an annual rate of 1.35 million, an increase of 3.8 percent from May and 4.7 percent from June 2015. Homes in the region sold for a median price of $199,900, a year-over-year increase of 5.7 percent.