pronounce question

[vkhu]

I sometimes see people addressing a group of people like a company or a council using "they" but other times "it" is used. For eg (I made them up):

"Random.Ltd said they didn't have anything to do with it"
"Random.Ltd won't be able to get out of this mess by itself"

Can some one explain to me when to use singular pronounces and when to use plural ones?

[JohnParis]

American Airlines is pleased to announce new routes to the UK.
British Airlines are pleased to announce new routes to the USA.

It's an AmE, BrE distinction. Both are used widely. Both are acceptable.

[emsr2d2]

I sometimes see people addressing a group of people like a company or a council using "they" but other times "it" is used. For eg (I made them up):

"Random.Ltd said they didn't have anything to do with it"
"Random.Ltd won't be able to get out of this mess by itself"

Can some one explain to me when to use singular pronounces and when to use plural ones?

I think you mean "pronoun(s)", not "pronounce", which is a verb. So your title should read "Question about pronouns".