You can use the Share API
you can retrieve the posts of a company with the Find Shares by Owner:
GET
https://api.linkedin.com/v2/shares?q=owners&owners={URN}&sharesPerOwner=100
{
"activity": "urn:li:activity:12345657",
"content": {
"contentEntities": [
{
"entity": "urn:li:article:0",
"entityLocation": "https://www.example.com/content.html",
"thumbnails": [
{
"imageSpecificContent": {},
"resolvedUrl": "https://www.example.com/image.jpg"
}
]
}
],
"description": "content description",
"title": "Test Share with Content"
},
"created": {
"actor": "urn:li:person:A8xe03Qt10",
"time": 1471967236000
},
"distribution": {
"linkedInDistributionTarget": {}
},
"id": "6173878065928642560",
"lastModified": {
"actor": "urn:li:person:A8xe03Qt10",
"time": 1471967237000
},
"owner": "urn:li:organization:1000",
"text": {
"text": "Test Share!"
} }
And about the analytics you can use the Retrieve a Summary of Social Actions API:
GET
https://api.linkedin.com/v2/socialActions/{shareUrn|ugcPostUrn|commentUrn}
{
"commentsSummary": {
"totalFirstLevelComments": 4,
"aggregatedTotalComments": 9
},
"$URN": "urn:li:activity:6296748651834277888",
"likesSummary": {
"likedByCurrentUser": false,
"totalLikes": 226
}
}
Hope this help