noun or participle of the word "counting" in a sentence.

[andrew495]

Hi.
While reading, I met a sentence below. I was trying to figure out the meaning of the bolded part of the sentence and got confused. Because it has not a verb (action) instead it has the word "counting", which is formed from the verb "count". And I asked myself whether it is noun or participle or something else? And I could not answer.
Here is the sentence.

In real estate parlance, representing either a buyer or a seller is called a "side", with the representation of both counting as two sides.

If the bolded part means as "The representation of both is counted as two side" there must be a passive voice participle - counted. But if we put in "counted" instead of "counting" there will be the sentence that has a verb in the past tence. It is also not well (in my opinion).
Or may be the author wants to say, as " Real Estate parlance counts the representation of both as two sides".

Would you please help me to get the meaning of the bolded part, especially the function of the word "counting"?
Many thanks in advance.

 

[Rover_KE]

While reading,...

What were you reading, Andrew, and who wrote it?

Please ... always tell us the source of any text you quote.

 

[andrew495]

Please ... always tell us the source of any text you quote.

It is Mr Buffett's letter to shareholders of Berkshire Company.

The context.

HomeServices owns 38 realty companies with more than 29,000 agents who operate in 28 states. Last
year it purchased four realtors, including Houlihan Lawrence, the leader in New York’s Westchester County (in a
transaction that closed shortly after yearend).
In real estate parlance, representing either a buyer or a seller is called a “side,” with the representation of
both counting as two sides. Last year, our owned realtors participated in 244,000 sides, totaling $86 billion in
volume.
HomeServices also franchises many operations throughout the country that use our name. We like both
aspects of the real estate business and expect to acquire many realtors and franchisees during the next decade.

 

[jutfrank]

Or may be the author wants to say, as " Real Estate parlance counts the representation of both as two sides".

Yes.