Pharma giant Pfizer, which is currently in a battle for Britain's AstraZeneca, will report its first-quarter results today, for the three months to the end of March.

Analysts are forecasting earnings per share of $0.55 for the quarter. The reported EPS for the same quarter last year was $0.54.

The company is working on its next move in a $100 billion takeover of AstraZeneca after having two bids rejected.

Pfizer chief executive Ian Read said a merger would boost Pfizer's earnings the first full year after deal is completed, adding that earnings per share growth would accelerate in the subsequent years.

He said the main reason Pfizer was making the bid for AstraZeneca was for tax reasons. If the bid was successful, Pfizer would merge the two companies into a UK holding company with a UK tax domicile, as the corporation tax rates will fall to 20 per cent in Britain next year, compared with 35 per cent in the US.

A merger would thus allow Pfizer to reduce its tax bill on a £42 billion cash pile from overseas earnings that it had yet to repatriate.

On the subject of tax inversion and takeovers, Perrigo is also reporting earnings this week.

The company, which recently acquired Irish biotech firm Elan, last posted quarterly earnings in February, reporting revenue of $979 million, below analyst estimates. However, revenue was up 10.9 per cent compared to the same quarter last year. The company reported earnings per share of $1.87 for the quarter, beating the consensus estimate of $1.59.

Perrigo expects EPS on an adjusted basis for fiscal 2014 to be in the range of $6.45-$6.70. Analysts expect Perrigo will post $6.62 EPS for the current fiscal year.

Last week, the board of directors of Perrigo declared a quarterly dividend of 10.5 cents a share, payable on June 17th.