status of investment held by amalganated compnay

[pawansingla]

A company ourchased certain shares and held it as investment for three years. Subsequently company A amalgamated with company B. Company B sold those shares after holding it for four months? The assessee cliamed that the profit on sale of these shares is long term capital gain as per section 10(38) because period of holding of A company would also be included for recokned the period of holding. However Assessing Officer does not agree with the contention. He says it is short term capital gain as shares were held by company B for 4 months only. Kindly advise with relevantt case laws? i am nit clear on the issue.