Apple and Samsung are key players in the smartphone market but recent analysis shows that Samsung is forecasted to increase its smartphone sales by 35 percent in 2013, compared to 33 percent sales increase by Apple in the same period. The increase in sales forecast means that Samsung will widen its lead over Apple in 2013.

Market researcher Strategy Analytics reported that global smartphone shipment will increase by 27 percent to 875 million smartphone units in 2013. Samsung is estimated to sell 290 million units and Apple 180 million smartphone units in 2013.

If both Samsung and Apple achieve the estimated sales figure, then Samsung will hold 33 percent of the smartphone market share in 2013, which is an increase of two percent from 2012. Apple will be at the second position with a 21 percent market share versus the 20 percent market share in 2012.

"We expect Samsung to slightly extend its lead over Apple this year because of its larger multitier product portfolio," said Neil Mawston, executive director at Strategy Analytics, in an e-mail interview with Reuters.

Samsung is expected to launch the Galaxy S4 and the Galaxy Note 3 in 2013. The predecessors of these smartphones, Galaxy S3 and Galaxy Note 2, have been the company's best-selling smartphones in 2012.

Apple has just the iPhone up against an array of smartphones offered by Samsung. Recent reports suggest that Apple may launch a cheaper version of its iPhone to penetrate the smartphone market further. Apple is speculated to launch its iPhone 5S in May or June this year and per Topeka Capital Markets, the company may release the iPhone 5S in various colors and screen sizes.

If Apple wants to minimize the market share gap with Samsung, then company will have to increase its smartphone portfolio with the introduction of more smartphones.

The year 2013 has just begun and it will be interesting to see what both the smartphone makers bring our way in the year ahead.